<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:7197e617-d31c-4ce8-969c-c56965ede58f,g:7693ecf2-84bd-4df7-b93c-138a355a34b7-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/ConsolidatedStatementsofOperationsUnaudited" xlink:type="simple" xlink:href="cfb-20210630.xsd#ConsolidatedStatementsofOperationsUnaudited"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/ConsolidatedStatementsofOperationsUnaudited" xlink:type="extended" id="if8335602265b4233a75892b32d3a884a_ConsolidatedStatementsofOperationsUnaudited">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndDividendIncomeOperatingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_a9044f12-1312-4fd4-927e-656d13e39b9c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_a9044f12-1312-4fd4-927e-656d13e39b9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxable_be10f8bb-cc65-4183-832f-569c8ecc2e99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxable_be10f8bb-cc65-4183-832f-569c8ecc2e99" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_1eea70a3-1bda-4e10-97fe-88a68523b390" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_1eea70a3-1bda-4e10-97fe-88a68523b390" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_4bc91b18-f74a-4424-8dcc-05cf281717ca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_4bc91b18-f74a-4424-8dcc-05cf281717ca" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendIncomeOperating_78ea84e9-d901-4d42-82f5-c5f9d77b7f42" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_DividendIncomeOperating_78ea84e9-d901-4d42-82f5-c5f9d77b7f42" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_7a8e4fb8-2682-4d16-91df-f21a16138cd3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperatingAbstract_e67bcf39-2093-48a3-a926-0f2012129b92" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_7a8e4fb8-2682-4d16-91df-f21a16138cd3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_5696f1b0-ce66-40e7-a53b-3984414d879c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:to="loc_us-gaap_InterestExpenseDeposits_5696f1b0-ce66-40e7-a53b-3984414d879c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase_986e75d1-354c-4f93-b0fe-66906c4d1409" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:to="loc_us-gaap_InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase_986e75d1-354c-4f93-b0fe-66906c4d1409" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm_7e0d1745-01bd-440c-83c4-3ffba0e8595c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:to="loc_us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm_7e0d1745-01bd-440c-83c4-3ffba0e8595c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOtherShortTermBorrowings_9e1c01b1-3443-4d3a-ae61-b4e2e56de405" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseOtherShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:to="loc_us-gaap_InterestExpenseOtherShortTermBorrowings_9e1c01b1-3443-4d3a-ae61-b4e2e56de405" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_1628bb85-2be5-40d5-a632-956fe1085daf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestExpenseAbstract_8fa51b66-206b-4a8d-b7c2-a79fd9a7e4d8" xlink:to="loc_us-gaap_InterestExpense_1628bb85-2be5-40d5-a632-956fe1085daf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_c60712cb-5e6e-464a-81e7-37eb4a7a48f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_c60712cb-5e6e-464a-81e7-37eb4a7a48f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_eb20386f-9cc3-4c64-bac9-eab2df6904fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_eb20386f-9cc3-4c64-bac9-eab2df6904fc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_9e8883f4-45bf-4a8f-8f7a-9419133f5ff5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_9e8883f4-45bf-4a8f-8f7a-9419133f5ff5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0e0ae83b-cd0a-4968-a0d8-92657d2c427c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0e0ae83b-cd0a-4968-a0d8-92657d2c427c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_18ec1d4a-9a92-4dd7-9264-3e7d87879156" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_GainLossOnInvestments_18ec1d4a-9a92-4dd7-9264-3e7d87879156" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsuranceIncome_da5d67e3-4bf1-4df8-a227-defa3574332f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BankOwnedLifeInsuranceIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_BankOwnedLifeInsuranceIncome_da5d67e3-4bf1-4df8-a227-defa3574332f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_02ea81ab-272c-4945-9482-7d51ba091ba5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDerivativeInstrumentsNetPretax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_02ea81ab-272c-4945-9482-7d51ba091ba5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_da50bdc9-c830-4fac-a406-e564a9f9ab24" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_da50bdc9-c830-4fac-a406-e564a9f9ab24" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_4fbb3b75-9317-4927-8307-a5e8a533652e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_dc22d788-9518-4fb7-bdeb-c477efabc221" xlink:to="loc_us-gaap_NoninterestIncome_4fbb3b75-9317-4927-8307-a5e8a533652e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_fd8b4215-2283-4058-a4a5-7aa9e68c51aa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_LaborAndRelatedExpense_fd8b4215-2283-4058-a4a5-7aa9e68c51aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_c280bdaf-223c-47dc-985e-e7343317a929" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OccupancyNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_OccupancyNet_c280bdaf-223c-47dc-985e-e7343317a929" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_fb0ece7e-4e53-485d-8c50-f2336cc49b76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_ProfessionalFees_fb0ece7e-4e53-485d-8c50-f2336cc49b76" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_818ab3aa-3804-4274-9f2a-1f121fa7333a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalDepositInsuranceCorporationPremiumExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_818ab3aa-3804-4274-9f2a-1f121fa7333a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_a490cf13-801e-4509-ad32-bd6dde180d79" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_a490cf13-801e-4509-ad32-bd6dde180d79" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvertisingExpense_4a32cbbb-9ae2-453e-83a6-f3cf85775e14" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdvertisingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_AdvertisingExpense_4a32cbbb-9ae2-453e-83a6-f3cf85775e14" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Communication_58122fb3-4712-4d40-ba62-00cb436005de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Communication"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_Communication_58122fb3-4712-4d40-ba62-00cb436005de" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeclosedRealEstateExpense_c9b59bf7-a3e2-4d63-8614-f53d862a898e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeclosedRealEstateExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_ForeclosedRealEstateExpense_c9b59bf7-a3e2-4d63-8614-f53d862a898e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_7871ff6c-0a30-4811-a6b0-a4d74446dc4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_7871ff6c-0a30-4811-a6b0-a4d74446dc4b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_b81b39c0-8089-4d72-9f8f-2055efc280eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_OtherNoninterestExpense_b81b39c0-8089-4d72-9f8f-2055efc280eb" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_ea0d992d-e0b8-4c2a-b437-f8f567a6cc04" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_498c3941-1ffd-4796-8cc1-a9ab7aa712e4" xlink:to="loc_us-gaap_NoninterestExpense_ea0d992d-e0b8-4c2a-b437-f8f567a6cc04" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossAttributableToParent_82ccd843-7a48-4774-a773-071333c62ac3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_IncomeLossAttributableToParent_82ccd843-7a48-4774-a773-071333c62ac3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_113f42a5-2797-4bf2-b341-a208a79ce10b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_113f42a5-2797-4bf2-b341-a208a79ce10b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_34d8e308-8501-42db-b6d2-c35d9386814d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_NetIncomeLoss_34d8e308-8501-42db-b6d2-c35d9386814d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_0ea81055-81d3-47d6-8799-5b45a33f261d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_EarningsPerShareBasic_0ea81055-81d3-47d6-8799-5b45a33f261d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_b16c0a36-71bd-4f25-8f5e-c06a538889d4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_EarningsPerShareDiluted_b16c0a36-71bd-4f25-8f5e-c06a538889d4" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f3d6c99d-06d3-44c0-810c-0624b9d6a6e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0db8e750-c536-44c6-b77c-707044159289" xlink:to="loc_us-gaap_StatementTable_f3d6c99d-06d3-44c0-810c-0624b9d6a6e2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f3d6c99d-06d3-44c0-810c-0624b9d6a6e2" xlink:to="loc_srt_ProductOrServiceAxis_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b" xlink:to="loc_srt_ProductsAndServicesDomain_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_a7b4e8c9-17c7-4256-a50d-b95bce192df9" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_59ba2bcd-61a2-4f32-bbdc-02b18d6eee0b" xlink:to="loc_srt_ProductsAndServicesDomain_a7b4e8c9-17c7-4256-a50d-b95bce192df9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ServiceChargesAndFeesMember_75c90992-2b27-45a5-924e-5a9dbe342e6b" xlink:href="cfb-20210630.xsd#cfb_ServiceChargesAndFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a7b4e8c9-17c7-4256-a50d-b95bce192df9" xlink:to="loc_cfb_ServiceChargesAndFeesMember_75c90992-2b27-45a5-924e-5a9dbe342e6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ATMAndCreditCardInterchangeIncomeMember_dd6f8352-c57c-4b8c-80e3-221c98433e57" xlink:href="cfb-20210630.xsd#cfb_ATMAndCreditCardInterchangeIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a7b4e8c9-17c7-4256-a50d-b95bce192df9" xlink:to="loc_cfb_ATMAndCreditCardInterchangeIncomeMember_dd6f8352-c57c-4b8c-80e3-221c98433e57" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/ConsolidatedStatementsofStockholdersEquityUnaudited" xlink:type="simple" xlink:href="cfb-20210630.xsd#ConsolidatedStatementsofStockholdersEquityUnaudited"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/ConsolidatedStatementsofStockholdersEquityUnaudited" xlink:type="extended" id="i07af64f49f8444c49ebea1fb5fbb8b84_ConsolidatedStatementsofStockholdersEquityUnaudited">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_65504498-dbbe-441c-848f-c3634baf43ee" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_65504498-dbbe-441c-848f-c3634baf43ee" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_ceeb84c8-64ad-4057-ab79-ebcec0b6f96a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_SharesOutstanding_ceeb84c8-64ad-4057-ab79-ebcec0b6f96a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_26fba91f-ec1a-4700-b980-4efe287bf77a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_StockholdersEquity_26fba91f-ec1a-4700-b980-4efe287bf77a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_3f3a49f3-c896-4d86-aeb5-56ba79f9618b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_NetIncomeLoss_3f3a49f3-c896-4d86-aeb5-56ba79f9618b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_93e44fbb-ceac-41c3-af2f-b89c17df7410" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_93e44fbb-ceac-41c3-af2f-b89c17df7410" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_2913941c-cec6-45e3-892d-3f5946f0fcaf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_2913941c-cec6-45e3-892d-3f5946f0fcaf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_a7c09e4a-bd87-4ef1-8257-bd23eaeb8b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_a7c09e4a-bd87-4ef1-8257-bd23eaeb8b3a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_4c5da101-bf19-4bc6-81c8-38d0e55f3bad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_4c5da101-bf19-4bc6-81c8-38d0e55f3bad" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_11ced488-8ad6-48bd-80eb-d9f326916f3d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_11ced488-8ad6-48bd-80eb-d9f326916f3d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_AdjustmentsToAdditionalPaidInCapitalEmployeeReceivablesFromSaleOfStock_195ab9c0-055b-437d-b5e6-d98579bc3456" xlink:href="cfb-20210630.xsd#cfb_AdjustmentsToAdditionalPaidInCapitalEmployeeReceivablesFromSaleOfStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_cfb_AdjustmentsToAdditionalPaidInCapitalEmployeeReceivablesFromSaleOfStock_195ab9c0-055b-437d-b5e6-d98579bc3456" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_41333a92-7fde-49e8-b9c9-2054a490e2de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_fa0dc123-1e8c-42f3-95c8-f0ebd1c96b08" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_41333a92-7fde-49e8-b9c9-2054a490e2de" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_79d9cfc8-a6fd-47c1-8432-57b72938757c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_db752f53-4321-4b39-b7c5-edc3ae70e098" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_3fb0d3c9-c747-4a80-99e8-4f90490dcaa0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_65504498-dbbe-441c-848f-c3634baf43ee" xlink:to="loc_us-gaap_StatementTable_3fb0d3c9-c747-4a80-99e8-4f90490dcaa0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_6e0669c1-49d8-486e-a0f9-ae5247b56677" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_3fb0d3c9-c747-4a80-99e8-4f90490dcaa0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_6e0669c1-49d8-486e-a0f9-ae5247b56677" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6e0669c1-49d8-486e-a0f9-ae5247b56677_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6e0669c1-49d8-486e-a0f9-ae5247b56677" xlink:to="loc_us-gaap_EquityComponentDomain_6e0669c1-49d8-486e-a0f9-ae5247b56677_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6e0669c1-49d8-486e-a0f9-ae5247b56677" xlink:to="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_bbc597eb-08e5-4d0f-b6a9-2873dcbcaee3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:to="loc_us-gaap_CommonStockMember_bbc597eb-08e5-4d0f-b6a9-2873dcbcaee3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_2385e89a-842c-4652-b992-2edc56b1a4c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_2385e89a-842c-4652-b992-2edc56b1a4c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_e73fe4fb-5a37-4011-b702-0b0c73731918" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:to="loc_us-gaap_RetainedEarningsMember_e73fe4fb-5a37-4011-b702-0b0c73731918" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_cff61baf-674c-4700-a492-86e98bdbd81c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_cff61baf-674c-4700-a492-86e98bdbd81c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_e98876f6-966e-4cea-9bfd-0380237d370f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8050beca-1a31-462a-a73b-ba1b209457a8" xlink:to="loc_us-gaap_TreasuryStockMember_e98876f6-966e-4cea-9bfd-0380237d370f" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/SecuritiesAmortizedCostandFairValueofSecuritiesDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#SecuritiesAmortizedCostandFairValueofSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/SecuritiesAmortizedCostandFairValueofSecuritiesDetails" xlink:type="extended" id="i7b25610851384b07adbc532a28da4926_SecuritiesAmortizedCostandFairValueofSecuritiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_75db89fd-68ec-48f7-8610-a2ab203408dc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_75db89fd-68ec-48f7-8610-a2ab203408dc" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_2f8f2ab9-823d-4de8-87de-f64e8e27e7bf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_2f8f2ab9-823d-4de8-87de-f64e8e27e7bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_2212a801-e262-417d-8830-3af0c1fc4780" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_2212a801-e262-417d-8830-3af0c1fc4780" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_f7da7e22-a508-41af-8db9-8b1aae13fc8c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_f7da7e22-a508-41af-8db9-8b1aae13fc8c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_2c269b0d-5732-4ea4-b514-43f3f5204ef3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_ed4306b8-5711-4465-b787-0096b06932aa" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_2c269b0d-5732-4ea4-b514-43f3f5204ef3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_a95e440e-e7f5-420e-af26-8be5362bcf52" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_75db89fd-68ec-48f7-8610-a2ab203408dc" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_a95e440e-e7f5-420e-af26-8be5362bcf52" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_348e4cdc-b5b7-4102-9819-9c7e8ef7d908" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_a95e440e-e7f5-420e-af26-8be5362bcf52" xlink:to="loc_us-gaap_FinancialInstrumentAxis_348e4cdc-b5b7-4102-9819-9c7e8ef7d908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_348e4cdc-b5b7-4102-9819-9c7e8ef7d908_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_348e4cdc-b5b7-4102-9819-9c7e8ef7d908" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_348e4cdc-b5b7-4102-9819-9c7e8ef7d908_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_348e4cdc-b5b7-4102-9819-9c7e8ef7d908" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_c61ba0e6-aebc-4265-882c-4847bb55b5d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:to="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_c61ba0e6-aebc-4265-882c-4847bb55b5d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_02bb5a1e-6f91-43c0-b4b3-cbd767f3ac2f" xlink:href="cfb-20210630.xsd#cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:to="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_02bb5a1e-6f91-43c0-b4b3-cbd767f3ac2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_23d19205-3325-45e6-ab21-c3024e587c99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_23d19205-3325-45e6-ab21-c3024e587c99" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_a0cc48bc-04ee-4011-8c03-c8448bf501bd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e1bae06b-4d1c-4cf3-930d-5f2d9e7c3769" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_a0cc48bc-04ee-4011-8c03-c8448bf501bd" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/SecuritiesAmortizedCostandFairValuebyMaturityDateDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#SecuritiesAmortizedCostandFairValuebyMaturityDateDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/SecuritiesAmortizedCostandFairValuebyMaturityDateDetails" xlink:type="extended" id="id7a5f1f7211545419317d931edb6d357_SecuritiesAmortizedCostandFairValuebyMaturityDateDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa7703c2-d59d-4495-ae4d-aa0a75054b69" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa7703c2-d59d-4495-ae4d-aa0a75054b69" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_2b161e25-e651-457e-9fd9-2d6a799f2961" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_2b161e25-e651-457e-9fd9-2d6a799f2961" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis_2e3b60c5-321a-4559-84f0-81b8e2a03d70" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis_2e3b60c5-321a-4559-84f0-81b8e2a03d70" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis_0bedff9e-8fd4-434d-99ba-37822ed670fd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis_0bedff9e-8fd4-434d-99ba-37822ed670fd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis_2eed6958-982b-431d-8e0a-9e08fb6c7154" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis_2eed6958-982b-431d-8e0a-9e08fb6c7154" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_adee9dae-9636-48cf-858b-61cebd82cc25" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostBasisRollingMaturityAbstract_4190cb02-1ce5-4a73-8881-2529a086c797" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_adee9dae-9636-48cf-858b-61cebd82cc25" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa7703c2-d59d-4495-ae4d-aa0a75054b69" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_6822edff-7a17-4e72-b72c-16d9b97b2698" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_6822edff-7a17-4e72-b72c-16d9b97b2698" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_06eadd5b-e655-4266-8351-59296c165c3d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_06eadd5b-e655-4266-8351-59296c165c3d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_7b5a4dff-37fd-4ead-bba2-453498da7897" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_7b5a4dff-37fd-4ead-bba2-453498da7897" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue_515bd042-d694-4e01-80a3-607912972994" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue_515bd042-d694-4e01-80a3-607912972994" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_ed8974b9-6e07-474e-b289-e0b86bd509a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract_c1dab10f-8240-4090-b26f-3222734d6d2b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_ed8974b9-6e07-474e-b289-e0b86bd509a6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa7703c2-d59d-4495-ae4d-aa0a75054b69" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityWithinOneYearWeightedAverageYield_b46f6706-bfda-4422-bad1-3b6a9fac5fce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityWithinOneYearWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityWithinOneYearWeightedAverageYield_b46f6706-bfda-4422-bad1-3b6a9fac5fce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterOneThroughFiveYearsWeightedAverageYield_094d624e-632c-45f4-bd64-fd4d81a83f38" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterOneThroughFiveYearsWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterOneThroughFiveYearsWeightedAverageYield_094d624e-632c-45f4-bd64-fd4d81a83f38" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterFiveThroughTenYearsWeightedAverageYield_ae4035bc-1e47-4310-89c8-b596d5e947f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterFiveThroughTenYearsWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfterFiveThroughTenYearsWeightedAverageYield_ae4035bc-1e47-4310-89c8-b596d5e947f3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfter10YearsWeightedAverageYield_76e97562-17e7-42e2-9eb1-7c22e9f5fff4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityAfter10YearsWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityAfter10YearsWeightedAverageYield_76e97562-17e7-42e2-9eb1-7c22e9f5fff4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield_19a6818d-fb15-43c8-943a-7a709359b907" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract_76b57b8f-8697-4b4f-83cf-772598d87401" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleWeightedAverageYield_19a6818d-fb15-43c8-943a-7a709359b907" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2af058e0-ee96-4c01-955f-2335d2031343" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa7703c2-d59d-4495-ae4d-aa0a75054b69" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2af058e0-ee96-4c01-955f-2335d2031343" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_d29978c3-3548-4c9d-b479-ef3a937fa74f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2af058e0-ee96-4c01-955f-2335d2031343" xlink:to="loc_us-gaap_FinancialInstrumentAxis_d29978c3-3548-4c9d-b479-ef3a937fa74f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d29978c3-3548-4c9d-b479-ef3a937fa74f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d29978c3-3548-4c9d-b479-ef3a937fa74f" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d29978c3-3548-4c9d-b479-ef3a937fa74f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d29978c3-3548-4c9d-b479-ef3a937fa74f" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_0904fffc-8949-4c09-9d6a-0fbc3eb04f81" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:to="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_0904fffc-8949-4c09-9d6a-0fbc3eb04f81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_4e0f1a2d-e5a9-4b15-8b4c-0e51d8450a63" xlink:href="cfb-20210630.xsd#cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:to="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_4e0f1a2d-e5a9-4b15-8b4c-0e51d8450a63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_caefc114-46d3-4978-9581-832c74814cd7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_caefc114-46d3-4978-9581-832c74814cd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_527916ba-b89d-4864-a0ec-e2676bd8d5c0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_9a8c86a0-3252-4379-9aa3-ebd4fb3efca0" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_527916ba-b89d-4864-a0ec-e2676bd8d5c0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/SecuritiesUnrealizedLossesDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#SecuritiesUnrealizedLossesDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/SecuritiesUnrealizedLossesDetails" xlink:type="extended" id="i9f11d047b0314055bcadb705f8528a6f_SecuritiesUnrealizedLossesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_e411ff4f-ae07-40f2-9295-fc69f2969e97" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAbstract_7ee23b2a-ece3-4f44-8dc0-c73cca2e01a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_e411ff4f-ae07-40f2-9295-fc69f2969e97" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAbstract_7ee23b2a-ece3-4f44-8dc0-c73cca2e01a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract_7df04d49-c763-4e09-9988-b35a94252aa5" xlink:href="cfb-20210630.xsd#cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_7ee23b2a-ece3-4f44-8dc0-c73cca2e01a0" xlink:to="loc_cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract_7df04d49-c763-4e09-9988-b35a94252aa5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_b19d790c-a3ef-4e86-9f4c-9e8d60cbc4a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract_7df04d49-c763-4e09-9988-b35a94252aa5" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_b19d790c-a3ef-4e86-9f4c-9e8d60cbc4a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_5fe0c35c-0a58-4c06-92c3-3e989c592a14" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract_7df04d49-c763-4e09-9988-b35a94252aa5" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_5fe0c35c-0a58-4c06-92c3-3e989c592a14" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_9ad01d89-08bc-4916-846a-01b86c6f8e63" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesLessThanTwelveMonthsAbstract_7df04d49-c763-4e09-9988-b35a94252aa5" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_9ad01d89-08bc-4916-846a-01b86c6f8e63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract_49c931bb-baa9-4efa-b308-9a054537cd7d" xlink:href="cfb-20210630.xsd#cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_7ee23b2a-ece3-4f44-8dc0-c73cca2e01a0" xlink:to="loc_cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract_49c931bb-baa9-4efa-b308-9a054537cd7d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_d4a3159a-b2ff-4280-87f6-d4747b2dc7d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract_49c931bb-baa9-4efa-b308-9a054537cd7d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_d4a3159a-b2ff-4280-87f6-d4747b2dc7d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_41428a9c-11af-43a9-b63e-c414c3ad52e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract_49c931bb-baa9-4efa-b308-9a054537cd7d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_41428a9c-11af-43a9-b63e-c414c3ad52e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_0df6d0ad-1cc8-47dd-b4ed-f7b7f11e3ce0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_AvailableForSaleSecuritiesTwelveMonthsOrLongerAbstract_49c931bb-baa9-4efa-b308-9a054537cd7d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_0df6d0ad-1cc8-47dd-b4ed-f7b7f11e3ce0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract_49f4c612-c0a2-4255-80ce-1f15a0b5bb68" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAbstract_7ee23b2a-ece3-4f44-8dc0-c73cca2e01a0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract_49f4c612-c0a2-4255-80ce-1f15a0b5bb68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_75e67045-b003-4bcc-8dba-6624fbad51a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract_49f4c612-c0a2-4255-80ce-1f15a0b5bb68" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_75e67045-b003-4bcc-8dba-6624fbad51a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_3a3aa8dd-7d24-4671-8b1a-314b93289056" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract_49f4c612-c0a2-4255-80ce-1f15a0b5bb68" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_3a3aa8dd-7d24-4671-8b1a-314b93289056" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_3a291dc8-9631-4b29-8b20-2d8696f8fde7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract_49f4c612-c0a2-4255-80ce-1f15a0b5bb68" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_3a291dc8-9631-4b29-8b20-2d8696f8fde7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable_d9c26fab-a56f-4e71-86fa-5ad8ded5f24a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_e411ff4f-ae07-40f2-9295-fc69f2969e97" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable_d9c26fab-a56f-4e71-86fa-5ad8ded5f24a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_8d8a094c-01b4-43ac-b2e6-2ee765beec84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable_d9c26fab-a56f-4e71-86fa-5ad8ded5f24a" xlink:to="loc_us-gaap_FinancialInstrumentAxis_8d8a094c-01b4-43ac-b2e6-2ee765beec84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8d8a094c-01b4-43ac-b2e6-2ee765beec84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_8d8a094c-01b4-43ac-b2e6-2ee765beec84" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8d8a094c-01b4-43ac-b2e6-2ee765beec84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_8d8a094c-01b4-43ac-b2e6-2ee765beec84" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_3bbf375a-eae0-46df-aed5-400e1ca611ee" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:to="loc_us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_3bbf375a-eae0-46df-aed5-400e1ca611ee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_e9262d88-cad9-49dc-b794-de7086ffa0e1" xlink:href="cfb-20210630.xsd#cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:to="loc_cfb_CollateralizedMortgageObligationsGovernmentSponsoredEntitiesMember_e9262d88-cad9-49dc-b794-de7086ffa0e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_239180eb-6bf2-45fd-a6db-f34c6dba1539" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_239180eb-6bf2-45fd-a6db-f34c6dba1539" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_c35de9c0-a8e4-4e40-a6a3-0c2d9f41f727" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4656444a-1593-46d9-aa19-d4407554518d" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_c35de9c0-a8e4-4e40-a6a3-0c2d9f41f727" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/SecuritiesNarrativeDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#SecuritiesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/SecuritiesNarrativeDetails" xlink:type="extended" id="i176f92a75218414da33f7fc02f488d51_SecuritiesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_995ca4b0-f1ff-444e-b459-3fa4ad9c1e83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_fad092c8-f1e8-4917-8ce5-db301004a2ca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquitySecuritiesFvNi"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_995ca4b0-f1ff-444e-b459-3fa4ad9c1e83" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_fad092c8-f1e8-4917-8ce5-db301004a2ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EquitySecuritiesFVNITerm_8bd1cfbc-3549-4865-815b-ff77e7d25d04" xlink:href="cfb-20210630.xsd#cfb_EquitySecuritiesFVNITerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_995ca4b0-f1ff-444e-b459-3fa4ad9c1e83" xlink:to="loc_cfb_EquitySecuritiesFVNITerm_8bd1cfbc-3549-4865-815b-ff77e7d25d04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EquitySecuritiesFVNIExtensionTerm_a78d069e-9f79-4750-822c-59972f83741e" xlink:href="cfb-20210630.xsd#cfb_EquitySecuritiesFVNIExtensionTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_995ca4b0-f1ff-444e-b459-3fa4ad9c1e83" xlink:to="loc_cfb_EquitySecuritiesFVNIExtensionTerm_a78d069e-9f79-4750-822c-59972f83741e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_b0239f16-7e29-4cff-bacc-45bb5de57641" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_995ca4b0-f1ff-444e-b459-3fa4ad9c1e83" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_b0239f16-7e29-4cff-bacc-45bb5de57641" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_b0239f16-7e29-4cff-bacc-45bb5de57641" xlink:to="loc_us-gaap_FinancialInstrumentAxis_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cf35122c-b685-40d9-bb82-3c1d09849631" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_b2dd90d1-e034-47ed-bfdf-942e5a90ebd6" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cf35122c-b685-40d9-bb82-3c1d09849631" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_ccca154e-64f9-435c-a68f-1a1688310c9f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cf35122c-b685-40d9-bb82-3c1d09849631" xlink:to="loc_us-gaap_MutualFundMember_ccca154e-64f9-435c-a68f-1a1688310c9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsMember_9273e012-efa7-4614-92ee-045cafab7070" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivateEquityFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cf35122c-b685-40d9-bb82-3c1d09849631" xlink:to="loc_us-gaap_PrivateEquityFundsMember_9273e012-efa7-4614-92ee-045cafab7070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PrivateEquitySecurityMember_16625ac9-eafa-4ff3-825c-aa2156e6e8c6" xlink:href="cfb-20210630.xsd#cfb_PrivateEquitySecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cf35122c-b685-40d9-bb82-3c1d09849631" xlink:to="loc_cfb_PrivateEquitySecurityMember_16625ac9-eafa-4ff3-825c-aa2156e6e8c6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLCategoryofLoansDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLCategoryofLoansDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLCategoryofLoansDetails" xlink:type="extended" id="ie90f97a0863a4f5c928aa423ea4df13f_LoansandAllowanceforLoanLossesALLLCategoryofLoansDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_0cf038eb-03a1-47bd-baff-47763e186cad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:to="loc_us-gaap_NotesReceivableGross_0cf038eb-03a1-47bd-baff-47763e186cad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_4f94f5c6-11a6-468b-bcf4-d38f360b0e8f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_4f94f5c6-11a6-468b-bcf4-d38f360b0e8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableDeferredIncome_d6630bc9-ba1a-4988-b646-0290b69b0376" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableDeferredIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:to="loc_us-gaap_FinancingReceivableDeferredIncome_d6630bc9-ba1a-4988-b646-0290b69b0376" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_a8caf87d-a629-46c6-845b-e0266f5a3f0b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:to="loc_us-gaap_NotesReceivableNet_a8caf87d-a629-46c6-845b-e0266f5a3f0b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_cf7bd440-ca49-4d67-b087-be55b58c9076" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3963a6f6-9705-4090-87df-2d44d83811e5" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_cf7bd440-ca49-4d67-b087-be55b58c9076" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_546158d9-0afd-4caf-a7ae-eb27165bd7b3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_cf7bd440-ca49-4d67-b087-be55b58c9076" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_546158d9-0afd-4caf-a7ae-eb27165bd7b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_546158d9-0afd-4caf-a7ae-eb27165bd7b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_546158d9-0afd-4caf-a7ae-eb27165bd7b3" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_546158d9-0afd-4caf-a7ae-eb27165bd7b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_546158d9-0afd-4caf-a7ae-eb27165bd7b3" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_dadf51c4-93a9-4dbc-a193-6dff2a1c05b2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_dadf51c4-93a9-4dbc-a193-6dff2a1c05b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_e6e3dd16-96b5-40e2-977a-be09acd1a166" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_e6e3dd16-96b5-40e2-977a-be09acd1a166" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_061e7732-5908-4ca3-af5a-21e6dbd102d5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_061e7732-5908-4ca3-af5a-21e6dbd102d5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_6d37c87d-8880-4e19-82d6-ae2ad93a3641" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_6d37c87d-8880-4e19-82d6-ae2ad93a3641" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_f05b46bd-a62a-4d0d-b864-c4881d430ede" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_f05b46bd-a62a-4d0d-b864-c4881d430ede" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_a67ebb4c-1dde-44de-8ecc-9c46fb638bd5" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_cfb_PaymentProtectionProgramMember_a67ebb4c-1dde-44de-8ecc-9c46fb638bd5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_4c0e21c6-b82a-4466-b640-6358640af176" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_7f44715c-3155-421c-bf04-a5aaae64bde3" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_4c0e21c6-b82a-4466-b640-6358640af176" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLActivitybyPortfolioSegmentandDisaggregationDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLActivitybyPortfolioSegmentandDisaggregationDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLActivitybyPortfolioSegmentandDisaggregationDetails" xlink:type="extended" id="i4c31e024aeba4118adc96ff54c1cdc8f_LoansandAllowanceforLoanLossesALLLActivitybyPortfolioSegmentandDisaggregationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_cb339faa-c596-494a-ad36-576be5a8a53d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_cb339faa-c596-494a-ad36-576be5a8a53d" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_524c23eb-c545-4961-ab81-7bc2a70c99d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_524c23eb-c545-4961-ab81-7bc2a70c99d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_c3002a5d-5167-4318-a0ef-a89c8b031cb6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_c3002a5d-5167-4318-a0ef-a89c8b031cb6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_baeb069a-c437-450f-b367-62162ba8798b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_baeb069a-c437-450f-b367-62162ba8798b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_67dbeee5-1cce-4f9d-b5ba-6cdc026a9326" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_ecd71493-1885-4d64-827d-08b18926b01e" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_67dbeee5-1cce-4f9d-b5ba-6cdc026a9326" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_73eade26-39c1-489d-9778-e8157857cc9b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_65b654b3-9b33-4871-9f89-88744393e493" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_cb339faa-c596-494a-ad36-576be5a8a53d" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_65b654b3-9b33-4871-9f89-88744393e493" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_65b654b3-9b33-4871-9f89-88744393e493" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_cb8e2fd5-10a7-4f35-a8d2-8dee07166f5a" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_92180dba-a277-4fcc-9066-c1012ce70659" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_92180dba-a277-4fcc-9066-c1012ce70659" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_3549e4ac-4a74-459e-8952-903e4f5b771b" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_3549e4ac-4a74-459e-8952-903e4f5b771b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_a9a4891a-96ad-42ed-94c5-39323d3db3e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_a9a4891a-96ad-42ed-94c5-39323d3db3e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_de311d94-6b5e-4a43-8bfa-e4b07742eb02" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_de311d94-6b5e-4a43-8bfa-e4b07742eb02" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_33b24733-a0e5-446d-bd46-c43d896d9ef9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_33b24733-a0e5-446d-bd46-c43d896d9ef9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_70b8f0aa-e2cb-4ea9-86b8-82824ad4fd40" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_cfb_PaymentProtectionProgramMember_70b8f0aa-e2cb-4ea9-86b8-82824ad4fd40" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_7b58c638-20a3-49e0-aba0-b4646627ba3f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_cfc29de4-9b54-4197-9fd7-01cb5812ba29" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_7b58c638-20a3-49e0-aba0-b4646627ba3f" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLAllowanceforLoanLossesDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLAllowanceforLoanLossesDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLAllowanceforLoanLossesDetails" xlink:type="extended" id="i0c8b70a316604a51b7eee644898e9eb2_LoansandAllowanceforLoanLossesALLLAllowanceforLoanLossesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_dac2bca9-8577-489a-9f39-c9d6ebd65391" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract_97e15b3d-f25a-48d0-8062-74bfc63f250d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_dac2bca9-8577-489a-9f39-c9d6ebd65391" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract_97e15b3d-f25a-48d0-8062-74bfc63f250d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_ff6552fd-e641-4e84-9bc3-dac3eca7e889" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract_97e15b3d-f25a-48d0-8062-74bfc63f250d" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_ff6552fd-e641-4e84-9bc3-dac3eca7e889" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment_4eff1bc3-3b63-4b2f-824c-6e95fe3bc0c8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract_97e15b3d-f25a-48d0-8062-74bfc63f250d" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment_4eff1bc3-3b63-4b2f-824c-6e95fe3bc0c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_12387e2f-9dab-49d1-bd17-c31325806254" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract_97e15b3d-f25a-48d0-8062-74bfc63f250d" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_12387e2f-9dab-49d1-bd17-c31325806254" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_FinancingReceivableAdditionalInformationAbstract_7aa91b7c-bc86-408d-8f6d-7df216967177" xlink:href="cfb-20210630.xsd#cfb_FinancingReceivableAdditionalInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_dac2bca9-8577-489a-9f39-c9d6ebd65391" xlink:to="loc_cfb_FinancingReceivableAdditionalInformationAbstract_7aa91b7c-bc86-408d-8f6d-7df216967177" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment_a34ef9c5-e8fe-4160-bd8c-3c14dd702da9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_FinancingReceivableAdditionalInformationAbstract_7aa91b7c-bc86-408d-8f6d-7df216967177" xlink:to="loc_us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment_a34ef9c5-e8fe-4160-bd8c-3c14dd702da9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment_5fbc5a0e-df77-4f98-a710-9e1eb3cde622" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_FinancingReceivableAdditionalInformationAbstract_7aa91b7c-bc86-408d-8f6d-7df216967177" xlink:to="loc_us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment_5fbc5a0e-df77-4f98-a710-9e1eb3cde622" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_4809f2fe-251b-4e23-bdc5-7e5c02f4480d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cfb_FinancingReceivableAdditionalInformationAbstract_7aa91b7c-bc86-408d-8f6d-7df216967177" xlink:to="loc_us-gaap_NotesReceivableGross_4809f2fe-251b-4e23-bdc5-7e5c02f4480d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_824194d0-5cc4-40d2-88c7-11ca1e65a2a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_dac2bca9-8577-489a-9f39-c9d6ebd65391" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_824194d0-5cc4-40d2-88c7-11ca1e65a2a0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_f4de71df-755c-443f-b3be-4183b8939d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_824194d0-5cc4-40d2-88c7-11ca1e65a2a0" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_f4de71df-755c-443f-b3be-4183b8939d6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_f4de71df-755c-443f-b3be-4183b8939d6a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_f4de71df-755c-443f-b3be-4183b8939d6a" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_f4de71df-755c-443f-b3be-4183b8939d6a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_f4de71df-755c-443f-b3be-4183b8939d6a" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_62242ab0-4485-46e5-beae-9216e402576c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_62242ab0-4485-46e5-beae-9216e402576c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_e9ee121b-d185-4f7c-b87f-c3d2be6cab0a" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_e9ee121b-d185-4f7c-b87f-c3d2be6cab0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_594e33bb-bf25-48e1-83f9-7b22504e179a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_594e33bb-bf25-48e1-83f9-7b22504e179a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_d62e875d-67e0-449e-84c8-644b05983ee8" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_d62e875d-67e0-449e-84c8-644b05983ee8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_1c87f1bc-8cca-4140-a9d2-eea2d616161c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_1c87f1bc-8cca-4140-a9d2-eea2d616161c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_a1d24197-652e-4316-8d80-a4e6e92d1701" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_cfb_PaymentProtectionProgramMember_a1d24197-652e-4316-8d80-a4e6e92d1701" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_13abeba8-3675-46e2-8d07-cc8004951250" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_5df5200b-0d33-4982-a8b5-c207fc94b5a0" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_13abeba8-3675-46e2-8d07-cc8004951250" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLInternalRiskRatingsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLInternalRiskRatingsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLInternalRiskRatingsDetails" xlink:type="extended" id="ie87d91ee793d44919fcbb525391928cc_LoansandAllowanceforLoanLossesALLLInternalRiskRatingsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_5d42de1c-b64e-4a58-acd4-f495d8495828" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_4b2d6eea-5a67-41c5-a477-b3e6e8e5bc29" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_5d42de1c-b64e-4a58-acd4-f495d8495828" xlink:to="loc_us-gaap_NotesReceivableGross_4b2d6eea-5a67-41c5-a477-b3e6e8e5bc29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_47c6997d-ec1d-4614-874e-f1a789c743db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_5d42de1c-b64e-4a58-acd4-f495d8495828" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_47c6997d-ec1d-4614-874e-f1a789c743db" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_94e00423-dc29-4292-8102-64a49b8685ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_47c6997d-ec1d-4614-874e-f1a789c743db" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_94e00423-dc29-4292-8102-64a49b8685ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_94e00423-dc29-4292-8102-64a49b8685ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_94e00423-dc29-4292-8102-64a49b8685ae" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_94e00423-dc29-4292-8102-64a49b8685ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_94e00423-dc29-4292-8102-64a49b8685ae" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_dc7de4cb-a400-41b3-b50e-2843f6f1996d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_dc7de4cb-a400-41b3-b50e-2843f6f1996d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_b5eaf142-9729-40ca-b1f7-4182ecf2c2c2" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_b5eaf142-9729-40ca-b1f7-4182ecf2c2c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_5a867c8f-1562-495c-9677-a457402769b0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_5a867c8f-1562-495c-9677-a457402769b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_18bbba87-2721-4968-8bfa-7566b969d820" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_18bbba87-2721-4968-8bfa-7566b969d820" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_beb07346-4dc9-4286-92f1-04244031cb72" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_beb07346-4dc9-4286-92f1-04244031cb72" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_05411a8c-afb4-4f14-af52-250ccaa6b2dc" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_cfb_PaymentProtectionProgramMember_05411a8c-afb4-4f14-af52-250ccaa6b2dc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_6246e0c1-16c3-4a4c-a9d5-952c241d677e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_42778712-f0f8-4e54-b9a7-24d8448d0e19" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_6246e0c1-16c3-4a4c-a9d5-952c241d677e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_5e5650b9-3f37-4b4a-9288-2c7319cd4fba" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_47c6997d-ec1d-4614-874e-f1a789c743db" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_5e5650b9-3f37-4b4a-9288-2c7319cd4fba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_5e5650b9-3f37-4b4a-9288-2c7319cd4fba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_5e5650b9-3f37-4b4a-9288-2c7319cd4fba" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_5e5650b9-3f37-4b4a-9288-2c7319cd4fba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_5e5650b9-3f37-4b4a-9288-2c7319cd4fba" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PassMember_94f9c294-eb43-419c-904a-c8c7ddb6493f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PassMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:to="loc_us-gaap_PassMember_94f9c294-eb43-419c-904a-c8c7ddb6493f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SpecialMentionMember_d6000650-5880-4b0d-af4d-5f31b78e584b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SpecialMentionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:to="loc_us-gaap_SpecialMentionMember_d6000650-5880-4b0d-af4d-5f31b78e584b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubstandardMember_1348aba6-d22c-4c3c-8a07-8d36d3e4b5e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubstandardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:to="loc_us-gaap_SubstandardMember_1348aba6-d22c-4c3c-8a07-8d36d3e4b5e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DoubtfulMember_1ea654e9-2e79-46d0-8623-0b46662a4613" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DoubtfulMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:to="loc_us-gaap_DoubtfulMember_1ea654e9-2e79-46d0-8623-0b46662a4613" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnlikelyToBeCollectedFinancingReceivableMember_30bbeceb-25dd-45cd-817f-b3b10fcbce25" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnlikelyToBeCollectedFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_d392d298-6aa4-46b4-a874-9c6010c2cdde" xlink:to="loc_us-gaap_UnlikelyToBeCollectedFinancingReceivableMember_30bbeceb-25dd-45cd-817f-b3b10fcbce25" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_8f24d7ff-2e03-4008-9497-949b99598aae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_47c6997d-ec1d-4614-874e-f1a789c743db" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_8f24d7ff-2e03-4008-9497-949b99598aae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_8f24d7ff-2e03-4008-9497-949b99598aae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_8f24d7ff-2e03-4008-9497-949b99598aae" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_8f24d7ff-2e03-4008-9497-949b99598aae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_714e8876-8482-4321-b296-2eab483c358c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_8f24d7ff-2e03-4008-9497-949b99598aae" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_714e8876-8482-4321-b296-2eab483c358c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformingFinancingReceivableMember_49707760-9b20-44c3-8314-e261d771242a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_714e8876-8482-4321-b296-2eab483c358c" xlink:to="loc_us-gaap_PerformingFinancingReceivableMember_49707760-9b20-44c3-8314-e261d771242a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonperformingFinancingReceivableMember_244d6873-ba86-4be3-bd9b-29ee914fcd76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonperformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_714e8876-8482-4321-b296-2eab483c358c" xlink:to="loc_us-gaap_NonperformingFinancingReceivableMember_244d6873-ba86-4be3-bd9b-29ee914fcd76" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLLoanAgingAnalysisDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLLoanAgingAnalysisDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLLoanAgingAnalysisDetails" xlink:type="extended" id="id3cec542900744b5b3dbe149c5ab96f9_LoansandAllowanceforLoanLossesALLLLoanAgingAnalysisDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_7aa2fa8f-251f-4ec9-b32b-d415155ca4be" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_f910be29-921f-46b9-a5aa-1ed80c56687c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_7aa2fa8f-251f-4ec9-b32b-d415155ca4be" xlink:to="loc_us-gaap_NotesReceivableGross_f910be29-921f-46b9-a5aa-1ed80c56687c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_3989bfe4-e0ec-4a33-8e4f-21e75d52303e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_7aa2fa8f-251f-4ec9-b32b-d415155ca4be" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_3989bfe4-e0ec-4a33-8e4f-21e75d52303e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_ac40de91-388b-4020-89c6-6e8d9c30d876" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_7aa2fa8f-251f-4ec9-b32b-d415155ca4be" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_ac40de91-388b-4020-89c6-6e8d9c30d876" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_d1051c2f-8968-44d6-9aba-bd58d1c79428" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_ac40de91-388b-4020-89c6-6e8d9c30d876" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_d1051c2f-8968-44d6-9aba-bd58d1c79428" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d1051c2f-8968-44d6-9aba-bd58d1c79428_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_d1051c2f-8968-44d6-9aba-bd58d1c79428" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d1051c2f-8968-44d6-9aba-bd58d1c79428_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_d1051c2f-8968-44d6-9aba-bd58d1c79428" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_071e2d08-a031-4cbe-9843-273b2ca734d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_071e2d08-a031-4cbe-9843-273b2ca734d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_ffa2d478-2b19-4ebc-b3bf-7d599f5922ce" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_ffa2d478-2b19-4ebc-b3bf-7d599f5922ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_72163cad-d9aa-4c07-8b50-fc5f8796d7db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_72163cad-d9aa-4c07-8b50-fc5f8796d7db" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_20a2b029-cee7-405e-be07-91aea50d19de" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_20a2b029-cee7-405e-be07-91aea50d19de" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_fbed34cf-645d-4c52-802f-f6ebe7c0bb4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_fbed34cf-645d-4c52-802f-f6ebe7c0bb4b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_586e4ff4-a3a0-4998-9f00-b97555c21ada" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_cfb_PaymentProtectionProgramMember_586e4ff4-a3a0-4998-9f00-b97555c21ada" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_118ba677-4a81-4752-ba3c-116ce0e334c5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_4a3118b5-94d8-4051-9f1a-e953b6dcd46f" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_118ba677-4a81-4752-ba3c-116ce0e334c5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_a6ac05df-4558-4860-a97f-1a2e15b30bb2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_ac40de91-388b-4020-89c6-6e8d9c30d876" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_a6ac05df-4558-4860-a97f-1a2e15b30bb2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_a6ac05df-4558-4860-a97f-1a2e15b30bb2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_a6ac05df-4558-4860-a97f-1a2e15b30bb2" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_a6ac05df-4558-4860-a97f-1a2e15b30bb2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_ea047418-2289-4c07-8cb4-013c754024d4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_a6ac05df-4558-4860-a97f-1a2e15b30bb2" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_ea047418-2289-4c07-8cb4-013c754024d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetPastDueMember_730755eb-273a-4086-b875-1c8b960d11bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialAssetPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_ea047418-2289-4c07-8cb4-013c754024d4" xlink:to="loc_us-gaap_FinancialAssetPastDueMember_730755eb-273a-4086-b875-1c8b960d11bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_f56bb653-fe17-4b18-9cbb-26287165d5a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialAssetPastDueMember_730755eb-273a-4086-b875-1c8b960d11bc" xlink:to="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_f56bb653-fe17-4b18-9cbb-26287165d5a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_e356753d-090f-4708-915c-9dc3fc617074" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialAssetPastDueMember_730755eb-273a-4086-b875-1c8b960d11bc" xlink:to="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_e356753d-090f-4708-915c-9dc3fc617074" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_66266494-7448-401c-9c24-456862422179" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialAssetPastDueMember_730755eb-273a-4086-b875-1c8b960d11bc" xlink:to="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_66266494-7448-401c-9c24-456862422179" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetNotPastDueMember_7359ec94-ee95-48dd-a62b-e97daaef724e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialAssetNotPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_ea047418-2289-4c07-8cb4-013c754024d4" xlink:to="loc_us-gaap_FinancialAssetNotPastDueMember_7359ec94-ee95-48dd-a62b-e97daaef724e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLImpairedLoansDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLImpairedLoansDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLImpairedLoansDetails" xlink:type="extended" id="i29f08c40cb1049f5a06e95f6e83d3306_LoansandAllowanceforLoanLossesALLLImpairedLoansDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableImpairedLineItems_b4c4eef0-836d-4bc1-94ad-97497eafd21d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableImpairedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract_fe985143-81e1-473e-81b7-1bb491afcab5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_b4c4eef0-836d-4bc1-94ad-97497eafd21d" xlink:to="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract_fe985143-81e1-473e-81b7-1bb491afcab5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment_02b672a3-bcf1-475d-89b3-c8770b23e041" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract_fe985143-81e1-473e-81b7-1bb491afcab5" xlink:to="loc_us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment_02b672a3-bcf1-475d-89b3-c8770b23e041" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment_87487029-730b-4451-8f33-2b793bb2e328" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract_fe985143-81e1-473e-81b7-1bb491afcab5" xlink:to="loc_us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment_87487029-730b-4451-8f33-2b793bb2e328" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestment_0c7b4fd3-a332-42e1-aa29-bce8666ef41c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableRecordedInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract_fe985143-81e1-473e-81b7-1bb491afcab5" xlink:to="loc_us-gaap_ImpairedFinancingReceivableRecordedInvestment_0c7b4fd3-a332-42e1-aa29-bce8666ef41c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract_ab370fb0-ad2c-4751-bbd3-e2ab54b273dd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_b4c4eef0-836d-4bc1-94ad-97497eafd21d" xlink:to="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract_ab370fb0-ad2c-4751-bbd3-e2ab54b273dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance_85a4db07-ec4f-4d52-b713-6428158dcf43" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract_ab370fb0-ad2c-4751-bbd3-e2ab54b273dd" xlink:to="loc_us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance_85a4db07-ec4f-4d52-b713-6428158dcf43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance_a82eda73-5ff3-45a0-b237-093992f00785" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract_ab370fb0-ad2c-4751-bbd3-e2ab54b273dd" xlink:to="loc_us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance_a82eda73-5ff3-45a0-b237-093992f00785" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance_cd99ee76-fff5-49d3-aa47-c17f2bf6629a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract_ab370fb0-ad2c-4751-bbd3-e2ab54b273dd" xlink:to="loc_us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance_cd99ee76-fff5-49d3-aa47-c17f2bf6629a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableRelatedAllowance_330f49b9-354f-455d-91f8-05b298af03e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableRelatedAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_b4c4eef0-836d-4bc1-94ad-97497eafd21d" xlink:to="loc_us-gaap_ImpairedFinancingReceivableRelatedAllowance_330f49b9-354f-455d-91f8-05b298af03e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_f63e246d-47a5-46dd-85df-9e3859763dea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfImpairedFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_b4c4eef0-836d-4bc1-94ad-97497eafd21d" xlink:to="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_f63e246d-47a5-46dd-85df-9e3859763dea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_87153047-aa26-4d4d-8bf3-b6585a7b11ec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_f63e246d-47a5-46dd-85df-9e3859763dea" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_87153047-aa26-4d4d-8bf3-b6585a7b11ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_87153047-aa26-4d4d-8bf3-b6585a7b11ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_87153047-aa26-4d4d-8bf3-b6585a7b11ec" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_87153047-aa26-4d4d-8bf3-b6585a7b11ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_87153047-aa26-4d4d-8bf3-b6585a7b11ec" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_662de01f-3786-4684-b37d-28d39376ba4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_662de01f-3786-4684-b37d-28d39376ba4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_a614aa8d-9e59-4aed-bf6b-1fb5dd116a7c" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_a614aa8d-9e59-4aed-bf6b-1fb5dd116a7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_841c862b-c4af-4fa0-84aa-8eb3ea520843" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_841c862b-c4af-4fa0-84aa-8eb3ea520843" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_c3a3b06c-f0ab-4177-ba71-d66c22da9723" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_c3a3b06c-f0ab-4177-ba71-d66c22da9723" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_3e6a461c-2698-4d73-987f-c80fb3b3205f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_3e6a461c-2698-4d73-987f-c80fb3b3205f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_e1837d1c-5bab-4b8c-9bb7-87f9be80c992" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_cfb_PaymentProtectionProgramMember_e1837d1c-5bab-4b8c-9bb7-87f9be80c992" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_65acfe3d-4c36-4ab1-8d88-1ccb3fd7e11c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_02dab919-aed0-406a-bf15-7866dbde313b" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_65acfe3d-4c36-4ab1-8d88-1ccb3fd7e11c" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLImpairedLoanInterestIncomeandAverageImpairedLoansDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLImpairedLoanInterestIncomeandAverageImpairedLoansDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLImpairedLoanInterestIncomeandAverageImpairedLoansDetails" xlink:type="extended" id="if4c90bd5d768409d832a86aa607be3e3_LoansandAllowanceforLoanLossesALLLImpairedLoanInterestIncomeandAverageImpairedLoansDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableImpairedLineItems_32d0ed76-c4bd-4355-8bef-09b73f65f030" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableImpairedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod_fa68106d-fecb-49df-b9c3-58d096d2f5ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_32d0ed76-c4bd-4355-8bef-09b73f65f030" xlink:to="loc_us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod_fa68106d-fecb-49df-b9c3-58d096d2f5ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment_c9b8d8cf-d717-4bcf-97e7-412862e7c765" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_32d0ed76-c4bd-4355-8bef-09b73f65f030" xlink:to="loc_us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment_c9b8d8cf-d717-4bcf-97e7-412862e7c765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_952f9417-c159-4e09-88a3-bf6bdc5ac80e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfImpairedFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableImpairedLineItems_32d0ed76-c4bd-4355-8bef-09b73f65f030" xlink:to="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_952f9417-c159-4e09-88a3-bf6bdc5ac80e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_b6997724-8f7b-413a-ba9e-90e9e6a1123c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfImpairedFinancingReceivableTable_952f9417-c159-4e09-88a3-bf6bdc5ac80e" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_b6997724-8f7b-413a-ba9e-90e9e6a1123c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_b6997724-8f7b-413a-ba9e-90e9e6a1123c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_b6997724-8f7b-413a-ba9e-90e9e6a1123c" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_b6997724-8f7b-413a-ba9e-90e9e6a1123c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_b6997724-8f7b-413a-ba9e-90e9e6a1123c" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_ad58fe50-a48f-4ba5-bb08-9324c9e91eb0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_ad58fe50-a48f-4ba5-bb08-9324c9e91eb0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_3b05b606-5a43-40b8-b95e-8814e6988841" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_3b05b606-5a43-40b8-b95e-8814e6988841" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_44621518-f084-448f-8b18-d2d1f78f0431" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_44621518-f084-448f-8b18-d2d1f78f0431" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_839db337-0797-42b8-a4ed-304fcc0d64aa" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_839db337-0797-42b8-a4ed-304fcc0d64aa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_13532f7d-9fa4-4c93-ae7e-213547e46845" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_13532f7d-9fa4-4c93-ae7e-213547e46845" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_1f9e848e-57de-4a06-b112-3e3674307b95" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_cfb_PaymentProtectionProgramMember_1f9e848e-57de-4a06-b112-3e3674307b95" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_e6cef768-93ed-41fd-a9f8-0cc7f4a19204" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_3eb41ea3-8218-453a-b05d-94ec04da5ce6" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_e6cef768-93ed-41fd-a9f8-0cc7f4a19204" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLNonAccrualLoansDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLNonAccrualLoansDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLNonAccrualLoansDetails" xlink:type="extended" id="i5d52c4f4fe9d42b991a80df4cbeebe96_LoansandAllowanceforLoanLossesALLLNonAccrualLoansDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableNonaccrualStatusLineItems_f6db1803-7e2c-48ba-af43-febe1e2d17eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableNonaccrualStatusLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_75976abb-19aa-47f6-bf89-ee519afd6ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableNonaccrualStatusLineItems_f6db1803-7e2c-48ba-af43-febe1e2d17eb" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_75976abb-19aa-47f6-bf89-ee519afd6ce8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableNonaccrualTable_d681e860-3afb-48c3-ac9b-0e765bcd19e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableNonaccrualTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableNonaccrualStatusLineItems_f6db1803-7e2c-48ba-af43-febe1e2d17eb" xlink:to="loc_us-gaap_FinancingReceivableNonaccrualTable_d681e860-3afb-48c3-ac9b-0e765bcd19e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8759550e-d1ee-4b89-a219-f350f3354f48" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FinancingReceivableNonaccrualTable_d681e860-3afb-48c3-ac9b-0e765bcd19e5" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8759550e-d1ee-4b89-a219-f350f3354f48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8759550e-d1ee-4b89-a219-f350f3354f48_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8759550e-d1ee-4b89-a219-f350f3354f48" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8759550e-d1ee-4b89-a219-f350f3354f48_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8759550e-d1ee-4b89-a219-f350f3354f48" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_996cc23d-4bd8-4457-b512-2db07d035510" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_996cc23d-4bd8-4457-b512-2db07d035510" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_76ba9e79-f801-4310-8fa7-f19bc05c34b0" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_76ba9e79-f801-4310-8fa7-f19bc05c34b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_a9e8673f-1d1f-42c9-8b68-185c968934ea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_a9e8673f-1d1f-42c9-8b68-185c968934ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_43d23ee5-173e-48b8-9d73-106b81d09d3f" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_43d23ee5-173e-48b8-9d73-106b81d09d3f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_384bcb77-aa79-46b3-9ef3-c32f1722d7da" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_384bcb77-aa79-46b3-9ef3-c32f1722d7da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_b0671006-bf98-4cdf-8d48-c03005e38fc1" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_cfb_PaymentProtectionProgramMember_b0671006-bf98-4cdf-8d48-c03005e38fc1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_6787a890-8347-46a5-ae00-a13f06814663" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_d8cf98d6-42c3-4ebe-a20e-9d28f4ade516" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_6787a890-8347-46a5-ae00-a13f06814663" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLTroubledDebtRestructuringLoansDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#LoansandAllowanceforLoanLossesALLLTroubledDebtRestructuringLoansDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/LoansandAllowanceforLoanLossesALLLTroubledDebtRestructuringLoansDetails" xlink:type="extended" id="i3fec9a051a824e5885adc1b8dfb11986_LoansandAllowanceforLoanLossesALLLTroubledDebtRestructuringLoansDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2_96ae28b1-7d58-497f-9cfe-95b9cc98fd1c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2_96ae28b1-7d58-497f-9cfe-95b9cc98fd1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsNumberOfContracts2_6adc9d29-6460-459c-b3de-892ab5103147" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsNumberOfContracts2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_us-gaap_FinancingReceivableModificationsNumberOfContracts2_6adc9d29-6460-459c-b3de-892ab5103147" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsRecordedInvestment_1c46e5a6-2688-4f36-a48e-4f3b41f600f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsRecordedInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_us-gaap_FinancingReceivableModificationsRecordedInvestment_1c46e5a6-2688-4f36-a48e-4f3b41f600f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1_71846b2a-2db1-4027-af41-9ce089118822" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1_71846b2a-2db1-4027-af41-9ce089118822" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_FinancingReceivableAllowanceForCreditLossIncreaseDecreaseFromModification_7236164a-a952-45f0-912f-1ffd50908bdb" xlink:href="cfb-20210630.xsd#cfb_FinancingReceivableAllowanceForCreditLossIncreaseDecreaseFromModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_cfb_FinancingReceivableAllowanceForCreditLossIncreaseDecreaseFromModification_7236164a-a952-45f0-912f-1ffd50908bdb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_1899d89e-50ce-4278-a8fa-c9e0727ae4a4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableModificationsLineItems_265316a9-e132-486b-bf3c-a08ccc9b6ebe" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_1899d89e-50ce-4278-a8fa-c9e0727ae4a4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationAxis_bcb95473-fc30-4406-8f59-5d9b4cf0cd56" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoanRestructuringModificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_1899d89e-50ce-4278-a8fa-c9e0727ae4a4" xlink:to="loc_us-gaap_LoanRestructuringModificationAxis_bcb95473-fc30-4406-8f59-5d9b4cf0cd56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_bcb95473-fc30-4406-8f59-5d9b4cf0cd56_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_bcb95473-fc30-4406-8f59-5d9b4cf0cd56" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_bcb95473-fc30-4406-8f59-5d9b4cf0cd56_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_14b2d9c3-dc5b-422e-b25d-10ab8c16c7a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_bcb95473-fc30-4406-8f59-5d9b4cf0cd56" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_14b2d9c3-dc5b-422e-b25d-10ab8c16c7a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualInterestRateReductionMember_d25bf916-c451-4191-99da-85277b54d0c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractualInterestRateReductionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_14b2d9c3-dc5b-422e-b25d-10ab8c16c7a0" xlink:to="loc_us-gaap_ContractualInterestRateReductionMember_d25bf916-c451-4191-99da-85277b54d0c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtendedMaturityMember_590d6073-1e0c-4d7c-a03c-7258771e5a43" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ExtendedMaturityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_14b2d9c3-dc5b-422e-b25d-10ab8c16c7a0" xlink:to="loc_us-gaap_ExtendedMaturityMember_590d6073-1e0c-4d7c-a03c-7258771e5a43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentDeferralMember_d45ae6a9-91e8-4e23-a9ff-c166a13de07a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentDeferralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_14b2d9c3-dc5b-422e-b25d-10ab8c16c7a0" xlink:to="loc_us-gaap_PaymentDeferralMember_d45ae6a9-91e8-4e23-a9ff-c166a13de07a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8ea04048-08c8-42c1-99f8-f3bb343f5d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_1899d89e-50ce-4278-a8fa-c9e0727ae4a4" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8ea04048-08c8-42c1-99f8-f3bb343f5d0f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ea04048-08c8-42c1-99f8-f3bb343f5d0f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8ea04048-08c8-42c1-99f8-f3bb343f5d0f" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ea04048-08c8-42c1-99f8-f3bb343f5d0f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_8ea04048-08c8-42c1-99f8-f3bb343f5d0f" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_a8c3bf03-d8d9-4acf-9578-7513ae375277" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_a8c3bf03-d8d9-4acf-9578-7513ae375277" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_EnergyPortfolioSegmentMember_68144e8b-7d89-4970-aeaa-fb06f67851b8" xlink:href="cfb-20210630.xsd#cfb_EnergyPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_cfb_EnergyPortfolioSegmentMember_68144e8b-7d89-4970-aeaa-fb06f67851b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_b16b6f6b-4981-4c72-bfcc-3adc133b55f4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialRealEstatePortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_us-gaap_CommercialRealEstatePortfolioSegmentMember_b16b6f6b-4981-4c72-bfcc-3adc133b55f4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_d3a58267-5f36-4343-9547-8a02b55cbd68" xlink:href="cfb-20210630.xsd#cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_cfb_ConstructionAndLandDevelopmentPortfolioSegmentMember_d3a58267-5f36-4343-9547-8a02b55cbd68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialPortfolioSegmentMember_ef3e53a6-e147-4758-8f42-4eb5dea24dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResidentialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_us-gaap_ResidentialPortfolioSegmentMember_ef3e53a6-e147-4758-8f42-4eb5dea24dd3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_PaymentProtectionProgramMember_294a0cd7-6e50-438f-a264-1d1258685668" xlink:href="cfb-20210630.xsd#cfb_PaymentProtectionProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_cfb_PaymentProtectionProgramMember_294a0cd7-6e50-438f-a264-1d1258685668" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_1f513f14-4988-4f5e-979b-3a832f94f44f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_8ef6b01d-f1b4-4dd4-b101-1f20865c50e9" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_1f513f14-4988-4f5e-979b-3a832f94f44f" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/DerivativesandHedgingOutstandingDerivativesDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#DerivativesandHedgingOutstandingDerivativesDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/DerivativesandHedgingOutstandingDerivativesDetails" xlink:type="extended" id="ibce6e6ecd7a94553be3b4cc864c8b5bc_DerivativesandHedgingOutstandingDerivativesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_fbb26f51-05da-4977-9689-ad3d61a998b0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_ce70cfcd-c5b0-42dd-a161-f4eb91579ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_fbb26f51-05da-4977-9689-ad3d61a998b0" xlink:to="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_ce70cfcd-c5b0-42dd-a161-f4eb91579ba8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_21c1f107-d1e2-4421-a193-f989beac88d7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_fbb26f51-05da-4977-9689-ad3d61a998b0" xlink:to="loc_us-gaap_DerivativeNotionalAmount_21c1f107-d1e2-4421-a193-f989beac88d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_41bc21cc-18f0-454b-aea2-6bd7273abd42" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_fbb26f51-05da-4977-9689-ad3d61a998b0" xlink:to="loc_us-gaap_DerivativeTable_41bc21cc-18f0-454b-aea2-6bd7273abd42" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_6a24379a-242a-4372-a4e2-65cd7427482c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_41bc21cc-18f0-454b-aea2-6bd7273abd42" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_6a24379a-242a-4372-a4e2-65cd7427482c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6a24379a-242a-4372-a4e2-65cd7427482c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6a24379a-242a-4372-a4e2-65cd7427482c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6a24379a-242a-4372-a4e2-65cd7427482c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_107ba32c-ee3e-4680-8509-8bf15c392857" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6a24379a-242a-4372-a4e2-65cd7427482c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_107ba32c-ee3e-4680-8509-8bf15c392857" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_e5053ead-e02b-478c-be56-ffa26686acc7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_107ba32c-ee3e-4680-8509-8bf15c392857" xlink:to="loc_us-gaap_InterestRateSwapMember_e5053ead-e02b-478c-be56-ffa26686acc7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_c60c831c-3145-42fa-b171-69c7ec73882b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_41bc21cc-18f0-454b-aea2-6bd7273abd42" xlink:to="loc_us-gaap_HedgingDesignationAxis_c60c831c-3145-42fa-b171-69c7ec73882b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_c60c831c-3145-42fa-b171-69c7ec73882b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_c60c831c-3145-42fa-b171-69c7ec73882b" xlink:to="loc_us-gaap_HedgingDesignationDomain_c60c831c-3145-42fa-b171-69c7ec73882b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_e8870321-0f35-4e64-8f71-a8f1e4164ad0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_c60c831c-3145-42fa-b171-69c7ec73882b" xlink:to="loc_us-gaap_HedgingDesignationDomain_e8870321-0f35-4e64-8f71-a8f1e4164ad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_efe692e4-65a1-46fe-9ec4-eb4303d4d69a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_e8870321-0f35-4e64-8f71-a8f1e4164ad0" xlink:to="loc_us-gaap_NondesignatedMember_efe692e4-65a1-46fe-9ec4-eb4303d4d69a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/DerivativesandHedgingFairValueofDerivativesDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#DerivativesandHedgingFairValueofDerivativesDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/DerivativesandHedgingFairValueofDerivativesDetails" xlink:type="extended" id="i2aafd1f4968f4dd0b7ac147f4c98ff8b_DerivativesandHedgingFairValueofDerivativesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_cc6a87c7-56ae-48d5-a63a-ea102eca6f7b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_e9d190a0-efa7-4633-b7b4-e1967b9d71b7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_cc6a87c7-56ae-48d5-a63a-ea102eca6f7b" xlink:to="loc_us-gaap_DerivativeAssets_e9d190a0-efa7-4633-b7b4-e1967b9d71b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_b8f5f933-d2aa-487e-9db6-dd0707a7b567" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_cc6a87c7-56ae-48d5-a63a-ea102eca6f7b" xlink:to="loc_us-gaap_DerivativeLiabilities_b8f5f933-d2aa-487e-9db6-dd0707a7b567" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_98dcce20-dba3-4a03-9d87-1600e885c2c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_cc6a87c7-56ae-48d5-a63a-ea102eca6f7b" xlink:to="loc_us-gaap_DerivativeTable_98dcce20-dba3-4a03-9d87-1600e885c2c4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_96e6d5be-06f9-4015-a38e-c95b700c1622" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_98dcce20-dba3-4a03-9d87-1600e885c2c4" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_96e6d5be-06f9-4015-a38e-c95b700c1622" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_96e6d5be-06f9-4015-a38e-c95b700c1622_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_96e6d5be-06f9-4015-a38e-c95b700c1622" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_96e6d5be-06f9-4015-a38e-c95b700c1622_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_847925d2-cab4-4ffc-a757-c5a78152fc6d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_96e6d5be-06f9-4015-a38e-c95b700c1622" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_847925d2-cab4-4ffc-a757-c5a78152fc6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_82924e81-2863-4a1d-8970-0bfdab43afa2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_847925d2-cab4-4ffc-a757-c5a78152fc6d" xlink:to="loc_us-gaap_OtherAssetsMember_82924e81-2863-4a1d-8970-0bfdab43afa2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesMember_39795306-d4c8-4b38-8aac-4b99b8af9d9a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_847925d2-cab4-4ffc-a757-c5a78152fc6d" xlink:to="loc_us-gaap_OtherLiabilitiesMember_39795306-d4c8-4b38-8aac-4b99b8af9d9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_c298f43e-9235-40cf-95d6-f1185c6b171b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_98dcce20-dba3-4a03-9d87-1600e885c2c4" xlink:to="loc_us-gaap_HedgingDesignationAxis_c298f43e-9235-40cf-95d6-f1185c6b171b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_c298f43e-9235-40cf-95d6-f1185c6b171b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_c298f43e-9235-40cf-95d6-f1185c6b171b" xlink:to="loc_us-gaap_HedgingDesignationDomain_c298f43e-9235-40cf-95d6-f1185c6b171b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_ce6f334b-05a1-49a8-8a28-0363e14b79fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_c298f43e-9235-40cf-95d6-f1185c6b171b" xlink:to="loc_us-gaap_HedgingDesignationDomain_ce6f334b-05a1-49a8-8a28-0363e14b79fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_6236bb2d-c5dc-40f9-b57a-c69c92d6eaff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_ce6f334b-05a1-49a8-8a28-0363e14b79fa" xlink:to="loc_us-gaap_NondesignatedMember_6236bb2d-c5dc-40f9-b57a-c69c92d6eaff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_c89d7811-88d4-4f62-8367-dd2dac73305f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_98dcce20-dba3-4a03-9d87-1600e885c2c4" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_c89d7811-88d4-4f62-8367-dd2dac73305f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_c89d7811-88d4-4f62-8367-dd2dac73305f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_c89d7811-88d4-4f62-8367-dd2dac73305f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_c89d7811-88d4-4f62-8367-dd2dac73305f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_850588fd-850e-47be-b9b2-cc295b2880f8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_c89d7811-88d4-4f62-8367-dd2dac73305f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_850588fd-850e-47be-b9b2-cc295b2880f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_5d629e05-d241-4624-b57f-8d9e93f530f1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_850588fd-850e-47be-b9b2-cc295b2880f8" xlink:to="loc_us-gaap_InterestRateContractMember_5d629e05-d241-4624-b57f-8d9e93f530f1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/ChangeinAccumulatedOtherComprehensiveIncomeAOCIDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#ChangeinAccumulatedOtherComprehensiveIncomeAOCIDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/ChangeinAccumulatedOtherComprehensiveIncomeAOCIDetails" xlink:type="extended" id="ie5f4a3be75264ddeb77282c630bd9e0a_ChangeinAccumulatedOtherComprehensiveIncomeAOCIDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b640e42f-31d9-4467-aa02-22b8e10b0a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_51319cc4-a821-4a4b-8e7c-4a126c4c7b14" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b640e42f-31d9-4467-aa02-22b8e10b0a5b" xlink:to="loc_us-gaap_GainLossOnInvestments_51319cc4-a821-4a4b-8e7c-4a126c4c7b14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_c385ecb8-5bba-4c09-92d3-f756ee2124f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b640e42f-31d9-4467-aa02-22b8e10b0a5b" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_c385ecb8-5bba-4c09-92d3-f756ee2124f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_acc502eb-c0d5-484f-9902-fbb3404da09e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b640e42f-31d9-4467-aa02-22b8e10b0a5b" xlink:to="loc_us-gaap_NetIncomeLoss_acc502eb-c0d5-484f-9902-fbb3404da09e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2f8a044e-fa4d-4a5f-b726-9aab5c319f21" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b640e42f-31d9-4467-aa02-22b8e10b0a5b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2f8a044e-fa4d-4a5f-b726-9aab5c319f21" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_21f52aca-f431-4038-aeeb-66f6e0ff31ab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2f8a044e-fa4d-4a5f-b726-9aab5c319f21" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_21f52aca-f431-4038-aeeb-66f6e0ff31ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_21f52aca-f431-4038-aeeb-66f6e0ff31ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_21f52aca-f431-4038-aeeb-66f6e0ff31ab" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_21f52aca-f431-4038-aeeb-66f6e0ff31ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_47d347f3-f28d-4f2b-8219-504bbd2e2218" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_21f52aca-f431-4038-aeeb-66f6e0ff31ab" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_47d347f3-f28d-4f2b-8219-504bbd2e2218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_0586a739-21bc-4363-aff2-652b7d0cc27b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_47d347f3-f28d-4f2b-8219-504bbd2e2218" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_0586a739-21bc-4363-aff2-652b7d0cc27b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/RegulatoryMattersDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#RegulatoryMattersDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/RegulatoryMattersDetails" xlink:type="extended" id="ibecd36578dcf42d0bedc183952945855_RegulatoryMattersDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:to="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Capital_52eafcd4-ef56-4908-89fc-f864a346908a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Capital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_Capital_52eafcd4-ef56-4908-89fc-f864a346908a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalToRiskWeightedAssets_4fdb5547-b2bc-4e70-a2b0-ef38076c496c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_CapitalToRiskWeightedAssets_4fdb5547-b2bc-4e70-a2b0-ef38076c496c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequiredForCapitalAdequacy_737a0ed9-888c-4913-8e0b-e4547584bbf4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalRequiredForCapitalAdequacy"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_CapitalRequiredForCapitalAdequacy_737a0ed9-888c-4913-8e0b-e4547584bbf4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets_1df8008a-a650-4063-82b8-223d2f1969ba" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets_1df8008a-a650-4063-82b8-223d2f1969ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequiredToBeWellCapitalized_2870cd37-6a2e-4468-8478-dd11d0e1756c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalRequiredToBeWellCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_CapitalRequiredToBeWellCapitalized_2870cd37-6a2e-4468-8478-dd11d0e1756c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_fe6da024-d2d7-4470-a740-f87aa00deeaf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalAbstract_88a04f35-8d8d-46ed-84ec-bb42af67cdb6" xlink:to="loc_us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_fe6da024-d2d7-4470-a740-f87aa00deeaf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapital_52b6b468-142f-4544-a536-dabdcef5f98f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapital_52b6b468-142f-4544-a536-dabdcef5f98f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_c444e4eb-1688-42cc-b8cf-87ded1db37a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_c444e4eb-1688-42cc-b8cf-87ded1db37a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy_449068a4-e81d-44a8-89b8-9263ab0b5d74" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy_449068a4-e81d-44a8-89b8-9263ab0b5d74" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_dc90f1db-a5eb-4eef-843b-eec3589031d1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_dc90f1db-a5eb-4eef-843b-eec3589031d1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized_ed23e5d2-f961-4062-b205-1257b5dd9da1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized_ed23e5d2-f961-4062-b205-1257b5dd9da1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_e5b183f1-a92e-46a2-9485-c70c00a49f37" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneRiskBasedCapitalAbstract_25fa6cc6-be3d-4a7f-9a06-48e5628f8ab5" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_e5b183f1-a92e-46a2-9485-c70c00a49f37" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonEquityTierOneCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:to="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonEquityTierOneCapital_18c9e907-5292-44b4-9d65-d928fbd0bc1a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonEquityTierOneCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_us-gaap_CommonEquityTierOneCapital_18c9e907-5292-44b4-9d65-d928fbd0bc1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonEquityTierOneCapitalRatio_4e804ad0-c2b7-4526-a8e3-c31c8116777f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonEquityTierOneCapitalRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_us-gaap_CommonEquityTierOneCapitalRatio_4e804ad0-c2b7-4526-a8e3-c31c8116777f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonEquityTierOneCapitalRequiredForCapitalAdequacy_4c85bc9d-934d-4bf4-8df1-8323fa00a4a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonEquityTierOneCapitalRequiredForCapitalAdequacy"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_us-gaap_CommonEquityTierOneCapitalRequiredForCapitalAdequacy_4c85bc9d-934d-4bf4-8df1-8323fa00a4a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_CommonEquityTierOneCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_bf018294-e5bf-4f2b-baf4-e1705c455a39" xlink:href="cfb-20210630.xsd#cfb_CommonEquityTierOneCapitalRequiredForCapitalAdequacyToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_cfb_CommonEquityTierOneCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_bf018294-e5bf-4f2b-baf4-e1705c455a39" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonEquityTierOneCapitalRequiredToBeWellCapitalized_2e869b33-cfe6-45cc-a170-693f6cc6360a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonEquityTierOneCapitalRequiredToBeWellCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_us-gaap_CommonEquityTierOneCapitalRequiredToBeWellCapitalized_2e869b33-cfe6-45cc-a170-693f6cc6360a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_CommonEquityTierOneCapitalRequiredToBeWellCapitalizedRatio_658f79b1-0f31-4e09-bf6a-903586eb00d9" xlink:href="cfb-20210630.xsd#cfb_CommonEquityTierOneCapitalRequiredToBeWellCapitalizedRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommonEquityTierOneCapitalAbstract_7ba4be8e-746e-46ec-a928-99dccfb80e7a" xlink:to="loc_cfb_CommonEquityTierOneCapitalRequiredToBeWellCapitalizedRatio_658f79b1-0f31-4e09-bf6a-903586eb00d9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:to="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapital_ff1f982a-5c3d-4608-be7e-af9dd9148137" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapital_ff1f982a-5c3d-4608-be7e-af9dd9148137" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalToAverageAssets_85fff4c3-0bba-4668-82fe-9bb9907299eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalToAverageAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapitalToAverageAssets_85fff4c3-0bba-4668-82fe-9bb9907299eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy_a42edb52-700f-40c0-87e9-ae43c576c2b2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy_a42edb52-700f-40c0-87e9-ae43c576c2b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets_e0147121-a55e-48af-8714-c01e343e5c89" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets_e0147121-a55e-48af-8714-c01e343e5c89" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized_d2dbc0de-e7f8-4a6f-8c28-c50205301a19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized_d2dbc0de-e7f8-4a6f-8c28-c50205301a19" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets_46d16865-070e-4806-ad60-990a907d27fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TierOneLeverageCapitalAbstract_9b699e02-76aa-4131-9f1a-0a8625ab4e6e" xlink:to="loc_us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets_46d16865-070e-4806-ad60-990a907d27fa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_396dac8b-7d20-4a7c-a095-a50e4665f7f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_7f1a9b0d-4de5-41b9-a3ac-712a1621d5d0" xlink:to="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_396dac8b-7d20-4a7c-a095-a50e4665f7f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_2227c256-9f49-4a71-acd3-cf8b93628eb1" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_396dac8b-7d20-4a7c-a095-a50e4665f7f0" xlink:to="loc_srt_ConsolidatedEntitiesAxis_2227c256-9f49-4a71-acd3-cf8b93628eb1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2227c256-9f49-4a71-acd3-cf8b93628eb1_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2227c256-9f49-4a71-acd3-cf8b93628eb1" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2227c256-9f49-4a71-acd3-cf8b93628eb1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f8db3f76-3498-4bed-bad3-b32fd0692e3f" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_2227c256-9f49-4a71-acd3-cf8b93628eb1" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f8db3f76-3498-4bed-bad3-b32fd0692e3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_59690215-b8b8-4dc5-bdee-9904c3fed296" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_f8db3f76-3498-4bed-bad3-b32fd0692e3f" xlink:to="loc_srt_SubsidiariesMember_59690215-b8b8-4dc5-bdee-9904c3fed296" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/StockBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#StockBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/StockBasedCompensationNarrativeDetails" xlink:type="extended" id="i2ce3a22432b44e3690e738058d3d0ee3_StockBasedCompensationNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_65114efd-37f7-46f4-b8ca-f8be0f1a8e0a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_65114efd-37f7-46f4-b8ca-f8be0f1a8e0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_b2d9bdc1-cb64-466f-a0f6-44cc3740c20d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_b2d9bdc1-cb64-466f-a0f6-44cc3740c20d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_b23c67d5-7915-42cd-b254-566356de03b1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_b23c67d5-7915-42cd-b254-566356de03b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_b2459216-c5a0-4463-be8f-cf9d16276ee0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_b2459216-c5a0-4463-be8f-cf9d16276ee0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_cd07c59e-9e8f-42a7-9a42-2aa7c35d11d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_cd07c59e-9e8f-42a7-9a42-2aa7c35d11d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformanceMetricPeriod_fb86eccd-4f17-4ba3-8aec-6f7a379c3fe8" xlink:href="cfb-20210630.xsd#cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformanceMetricPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformanceMetricPeriod_fb86eccd-4f17-4ba3-8aec-6f7a379c3fe8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_c2ace294-0554-4ea7-94be-32a3a482896a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_c2ace294-0554-4ea7-94be-32a3a482896a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_5461f496-ff3b-4d66-928c-78865197dfc8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_5461f496-ff3b-4d66-928c-78865197dfc8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_90cc54a7-3438-4297-9d67-a9a9e53d2370" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_82b038b0-a0b8-4706-8e0f-6eecf6cc0bde" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_90cc54a7-3438-4297-9d67-a9a9e53d2370" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_258cdbf6-f9ff-49ce-8a46-688361e41f26" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_90cc54a7-3438-4297-9d67-a9a9e53d2370" xlink:to="loc_us-gaap_PlanNameAxis_258cdbf6-f9ff-49ce-8a46-688361e41f26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_258cdbf6-f9ff-49ce-8a46-688361e41f26_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_258cdbf6-f9ff-49ce-8a46-688361e41f26" xlink:to="loc_us-gaap_PlanNameDomain_258cdbf6-f9ff-49ce-8a46-688361e41f26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_a6eb932b-3a43-4adb-8276-efe47bcfdef7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_258cdbf6-f9ff-49ce-8a46-688361e41f26" xlink:to="loc_us-gaap_PlanNameDomain_a6eb932b-3a43-4adb-8276-efe47bcfdef7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_A2018OmnibusEquityIncentivePlanMember_ec36f3d8-57b9-4113-9646-1494c6fb36be" xlink:href="cfb-20210630.xsd#cfb_A2018OmnibusEquityIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a6eb932b-3a43-4adb-8276-efe47bcfdef7" xlink:to="loc_cfb_A2018OmnibusEquityIncentivePlanMember_ec36f3d8-57b9-4113-9646-1494c6fb36be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_24f30134-0e44-4801-9858-f792b44e7566" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_90cc54a7-3438-4297-9d67-a9a9e53d2370" xlink:to="loc_us-gaap_AwardTypeAxis_24f30134-0e44-4801-9858-f792b44e7566" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_24f30134-0e44-4801-9858-f792b44e7566_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_24f30134-0e44-4801-9858-f792b44e7566" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_24f30134-0e44-4801-9858-f792b44e7566_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_24f30134-0e44-4801-9858-f792b44e7566" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_cd4396d3-800d-4c6d-b938-b3feffcc29a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:to="loc_us-gaap_PerformanceSharesMember_cd4396d3-800d-4c6d-b938-b3feffcc29a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RestrictedStockUnitsAllOtherMember_e2ca992b-9f44-49b3-a023-f5b5639498fe" xlink:href="cfb-20210630.xsd#cfb_RestrictedStockUnitsAllOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:to="loc_cfb_RestrictedStockUnitsAllOtherMember_e2ca992b-9f44-49b3-a023-f5b5639498fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_a8b64e00-5d65-489a-b873-f2b2b30fb86f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:to="loc_us-gaap_RestrictedStockMember_a8b64e00-5d65-489a-b873-f2b2b30fb86f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_fe44a73c-09a0-4875-9947-a4a2b4c92627" xlink:href="cfb-20210630.xsd#cfb_RestrictedStockAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f53444c7-dd38-4638-ab3c-748122f6a78c" xlink:to="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_fe44a73c-09a0-4875-9947-a4a2b4c92627" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_7d0e0c41-6f85-4e6b-9227-087013279841" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_90cc54a7-3438-4297-9d67-a9a9e53d2370" xlink:to="loc_srt_RangeAxis_7d0e0c41-6f85-4e6b-9227-087013279841" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7d0e0c41-6f85-4e6b-9227-087013279841_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_7d0e0c41-6f85-4e6b-9227-087013279841" xlink:to="loc_srt_RangeMember_7d0e0c41-6f85-4e6b-9227-087013279841_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f4f68827-9d6b-4e58-8184-928a9dc7b9f4" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_7d0e0c41-6f85-4e6b-9227-087013279841" xlink:to="loc_srt_RangeMember_f4f68827-9d6b-4e58-8184-928a9dc7b9f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_db257b4b-b8d3-4690-aa73-9756c3ea3e39" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f4f68827-9d6b-4e58-8184-928a9dc7b9f4" xlink:to="loc_srt_MinimumMember_db257b4b-b8d3-4690-aa73-9756c3ea3e39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a6aae86c-a3f1-4394-922e-c61c2e7ee22a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f4f68827-9d6b-4e58-8184-928a9dc7b9f4" xlink:to="loc_srt_MaximumMember_a6aae86c-a3f1-4394-922e-c61c2e7ee22a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/StockBasedCompensationTotalStockBasedCompensationDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#StockBasedCompensationTotalStockBasedCompensationDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/StockBasedCompensationTotalStockBasedCompensationDetails" xlink:type="extended" id="i1b701c1a694a455f89f1578235322629_StockBasedCompensationTotalStockBasedCompensationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2cf39a3a-8365-4762-968a-084f648d1293" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_10814127-7ad5-4323-b3f1-64311685eeff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2cf39a3a-8365-4762-968a-084f648d1293" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_10814127-7ad5-4323-b3f1-64311685eeff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_365cb723-9d4e-4d18-8812-79e5bce65e0d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2cf39a3a-8365-4762-968a-084f648d1293" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_365cb723-9d4e-4d18-8812-79e5bce65e0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_d8f8be16-d570-4d4a-9dc9-31636a1dc737" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_365cb723-9d4e-4d18-8812-79e5bce65e0d" xlink:to="loc_us-gaap_AwardTypeAxis_d8f8be16-d570-4d4a-9dc9-31636a1dc737" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d8f8be16-d570-4d4a-9dc9-31636a1dc737_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_d8f8be16-d570-4d4a-9dc9-31636a1dc737" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d8f8be16-d570-4d4a-9dc9-31636a1dc737_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_d8f8be16-d570-4d4a-9dc9-31636a1dc737" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockAppreciationRightsSARSMember_b2da2945-3d83-4ccf-8c51-380cf6691283" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockAppreciationRightsSARSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:to="loc_us-gaap_StockAppreciationRightsSARSMember_b2da2945-3d83-4ccf-8c51-380cf6691283" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_629859fd-7ca4-4650-a972-f89ef3bd5cf5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:to="loc_us-gaap_PerformanceSharesMember_629859fd-7ca4-4650-a972-f89ef3bd5cf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_4aee52ae-3f3f-4a7d-bfe1-ce8e8b6c3fed" xlink:href="cfb-20210630.xsd#cfb_RestrictedStockAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:to="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_4aee52ae-3f3f-4a7d-bfe1-ce8e8b6c3fed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_816263ea-3b93-4979-af2b-829a3a804877" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a79c4c46-d337-4065-b3a3-12e2fbe195f3" xlink:to="loc_us-gaap_EmployeeStockMember_816263ea-3b93-4979-af2b-829a3a804877" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/StockBasedCompensationStatusandChangesinPerformanceBasedAwardsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#StockBasedCompensationStatusandChangesinPerformanceBasedAwardsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/StockBasedCompensationStatusandChangesinPerformanceBasedAwardsDetails" xlink:type="extended" id="if44bed62b1dd421da53c00446ae168b3_StockBasedCompensationStatusandChangesinPerformanceBasedAwardsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_95bb9c4d-be21-4354-9c20-7ea15fbde243" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_95bb9c4d-be21-4354-9c20-7ea15fbde243" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_b3d98501-55b2-48c2-ac51-24f9196cab9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_b3d98501-55b2-48c2-ac51-24f9196cab9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_5bc876e7-499f-44d9-8760-680f723d466c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_5bc876e7-499f-44d9-8760-680f723d466c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriod_840c761e-727c-44ce-89fb-0df5142d29f0" xlink:href="cfb-20210630.xsd#cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:to="loc_cfb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriod_840c761e-727c-44ce-89fb-0df5142d29f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_fea4fc5e-924e-40fe-bc46-4c60d975308d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_fea4fc5e-924e-40fe-bc46-4c60d975308d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_b9881bc9-b436-45a6-a482-704bf11a269f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_74d2a430-0f73-496f-bb53-58b63cb778e1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_b9881bc9-b436-45a6-a482-704bf11a269f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_fdf8d590-3c00-4f9b-b7dc-fe205ca51c9c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_95bb9c4d-be21-4354-9c20-7ea15fbde243" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_ceebf006-84ea-4aee-bf54-0fcf1dd88d10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_ceebf006-84ea-4aee-bf54-0fcf1dd88d10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f6d68fbf-9a04-41f8-bd19-1eae818934be" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f6d68fbf-9a04-41f8-bd19-1eae818934be" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ShareBasedCompensationArrangementsByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriodWeightedAverageGrantDateFairValue_b388040d-8624-42db-b303-8f2d3e0333b9" xlink:href="cfb-20210630.xsd#cfb_ShareBasedCompensationArrangementsByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:to="loc_cfb_ShareBasedCompensationArrangementsByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOtherShareIncreaseDecreaseInPeriodWeightedAverageGrantDateFairValue_b388040d-8624-42db-b303-8f2d3e0333b9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_b0267355-c63e-4552-86a9-6d838b9a8811" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_b0267355-c63e-4552-86a9-6d838b9a8811" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_51e6d68b-85b6-401c-afdf-6294c0c807ed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_6370c641-ad73-4072-a09a-f99d9e7e30c9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_51e6d68b-85b6-401c-afdf-6294c0c807ed" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_ed6b1f2c-43d9-47e0-b710-5de305a46913" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_0716052d-3f85-4ee1-81cc-ea3db42bb233" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_95bb9c4d-be21-4354-9c20-7ea15fbde243" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_0716052d-3f85-4ee1-81cc-ea3db42bb233" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_4c1be80b-82c5-4b74-9889-72016623b2c8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_0716052d-3f85-4ee1-81cc-ea3db42bb233" xlink:to="loc_us-gaap_AwardTypeAxis_4c1be80b-82c5-4b74-9889-72016623b2c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4c1be80b-82c5-4b74-9889-72016623b2c8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4c1be80b-82c5-4b74-9889-72016623b2c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4c1be80b-82c5-4b74-9889-72016623b2c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cea9724-7ed6-470f-afe0-6e37efaba30a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4c1be80b-82c5-4b74-9889-72016623b2c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cea9724-7ed6-470f-afe0-6e37efaba30a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_1af01488-4ad4-4147-a93f-8d950a38cd70" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cea9724-7ed6-470f-afe0-6e37efaba30a" xlink:to="loc_us-gaap_PerformanceSharesMember_1af01488-4ad4-4147-a93f-8d950a38cd70" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/StockBasedCompensationStatusandChangesinRSUsandRSAsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#StockBasedCompensationStatusandChangesinRSUsandRSAsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/StockBasedCompensationStatusandChangesinRSUsandRSAsDetails" xlink:type="extended" id="i6600e9dc41d34904babc3a3e9586dc87_StockBasedCompensationStatusandChangesinRSUsandRSAsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5cb221d6-dfcb-4b24-a7ab-412c84f4ef38" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5cb221d6-dfcb-4b24-a7ab-412c84f4ef38" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_39f56370-ef77-4b07-8806-8c1bd1d2c70d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_39f56370-ef77-4b07-8806-8c1bd1d2c70d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_128108ed-80bd-4eca-926c-8f1575d27e20" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_128108ed-80bd-4eca-926c-8f1575d27e20" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_da3b2fc5-cb9b-488f-a5b9-834a555c9cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_da3b2fc5-cb9b-488f-a5b9-834a555c9cf3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_8906ec82-502e-4d58-b3f9-3becbe630d76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f20b4e32-dc9d-4df6-9aad-74bbb707b135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_8906ec82-502e-4d58-b3f9-3becbe630d76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_129c6992-a396-4408-8597-e53c2424193f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5cb221d6-dfcb-4b24-a7ab-412c84f4ef38" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_18b33e54-f952-421a-a1a5-e913d4686843" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_18b33e54-f952-421a-a1a5-e913d4686843" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_168eb13f-033f-4f71-823f-91ac434d522e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_168eb13f-033f-4f71-823f-91ac434d522e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_8fca9fa4-3707-49e9-a52b-5217c789328c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_8fca9fa4-3707-49e9-a52b-5217c789328c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c1dbf892-8bcf-4179-85f3-1f8437068349" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f79c03bb-24cc-4157-ad62-96dba3629bf5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c1dbf892-8bcf-4179-85f3-1f8437068349" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6cdd6471-6807-4cb1-ad31-59b207498d8a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_83c6183b-eb6f-43bf-afd2-3376e213f928" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5cb221d6-dfcb-4b24-a7ab-412c84f4ef38" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_83c6183b-eb6f-43bf-afd2-3376e213f928" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c805cff2-c6dd-4403-8110-d1c57df58340" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_83c6183b-eb6f-43bf-afd2-3376e213f928" xlink:to="loc_us-gaap_AwardTypeAxis_c805cff2-c6dd-4403-8110-d1c57df58340" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c805cff2-c6dd-4403-8110-d1c57df58340_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c805cff2-c6dd-4403-8110-d1c57df58340" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c805cff2-c6dd-4403-8110-d1c57df58340_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3a6f9567-b3bb-43f5-b310-a6295e593503" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c805cff2-c6dd-4403-8110-d1c57df58340" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3a6f9567-b3bb-43f5-b310-a6295e593503" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_2f526551-ab7b-471c-a89e-8a5d3902b37d" xlink:href="cfb-20210630.xsd#cfb_RestrictedStockAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3a6f9567-b3bb-43f5-b310-a6295e593503" xlink:to="loc_cfb_RestrictedStockAndRestrictedStockUnitsMember_2f526551-ab7b-471c-a89e-8a5d3902b37d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsNonrecurringMeasurementsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#DisclosuresaboutFairValueofFinancialInstrumentsNonrecurringMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsNonrecurringMeasurementsDetails" xlink:type="extended" id="i5291d245969c42afbc8446506c53c874_DisclosuresaboutFairValueofFinancialInstrumentsNonrecurringMeasurementsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_688f3800-5e21-4e9d-947a-d3c467ce1b2b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ImpairedFinancingReceivableFairValueDisclosure_967998e9-c51e-455e-92bc-56388950b945" xlink:href="cfb-20210630.xsd#cfb_ImpairedFinancingReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_688f3800-5e21-4e9d-947a-d3c467ce1b2b" xlink:to="loc_cfb_ImpairedFinancingReceivableFairValueDisclosure_967998e9-c51e-455e-92bc-56388950b945" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RepossessedAssetsHeldForSaleFairValueDisclosure_027872d9-9e6e-4e0a-8d6f-529940e1d16e" xlink:href="cfb-20210630.xsd#cfb_RepossessedAssetsHeldForSaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_688f3800-5e21-4e9d-947a-d3c467ce1b2b" xlink:to="loc_cfb_RepossessedAssetsHeldForSaleFairValueDisclosure_027872d9-9e6e-4e0a-8d6f-529940e1d16e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_4576d711-2fc3-4baf-b574-7a7ca7a90829" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_688f3800-5e21-4e9d-947a-d3c467ce1b2b" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_4576d711-2fc3-4baf-b574-7a7ca7a90829" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_4576d711-2fc3-4baf-b574-7a7ca7a90829" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_753a7202-17e0-451b-9aed-22c10f7ab282" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_75d49b1b-5f2c-4925-9dc6-ffa9cc538b78" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_753a7202-17e0-451b-9aed-22c10f7ab282" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_e04f4c67-7d60-4d4c-8274-39d88cb2a17a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_753a7202-17e0-451b-9aed-22c10f7ab282" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_e04f4c67-7d60-4d4c-8274-39d88cb2a17a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_429f5879-64bf-421b-8f3b-f8af132ed883" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_4576d711-2fc3-4baf-b574-7a7ca7a90829" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_429f5879-64bf-421b-8f3b-f8af132ed883" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_429f5879-64bf-421b-8f3b-f8af132ed883_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_429f5879-64bf-421b-8f3b-f8af132ed883" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_429f5879-64bf-421b-8f3b-f8af132ed883_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d20bef72-b28e-4184-920e-1f64c5c5f22a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_429f5879-64bf-421b-8f3b-f8af132ed883" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d20bef72-b28e-4184-920e-1f64c5c5f22a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_5414808f-b82d-4cf3-a5cd-46dd1a5b027a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d20bef72-b28e-4184-920e-1f64c5c5f22a" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_5414808f-b82d-4cf3-a5cd-46dd1a5b027a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_756bc802-80f5-4d7b-a2fc-4a6bc3d45001" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d20bef72-b28e-4184-920e-1f64c5c5f22a" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_756bc802-80f5-4d7b-a2fc-4a6bc3d45001" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_d46d4ad0-37bc-4fcf-a7e9-28004b101e6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d20bef72-b28e-4184-920e-1f64c5c5f22a" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_d46d4ad0-37bc-4fcf-a7e9-28004b101e6b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsUnobservableInputsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#DisclosuresaboutFairValueofFinancialInstrumentsUnobservableInputsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsUnobservableInputsDetails" xlink:type="extended" id="i834556d6f9874aefabeb1af927201bb1_DisclosuresaboutFairValueofFinancialInstrumentsUnobservableInputsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ImpairedFinancingReceivableFairValueDisclosure_ca61d9a9-e756-422f-98f1-689d04022bdf" xlink:href="cfb-20210630.xsd#cfb_ImpairedFinancingReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:to="loc_cfb_ImpairedFinancingReceivableFairValueDisclosure_ca61d9a9-e756-422f-98f1-689d04022bdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ImpairedLoansMeasurementInput_3db41e97-23ed-46e7-bc7f-bd2f1bf7867e" xlink:href="cfb-20210630.xsd#cfb_ImpairedLoansMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:to="loc_cfb_ImpairedLoansMeasurementInput_3db41e97-23ed-46e7-bc7f-bd2f1bf7867e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_RepossessedAssetsHeldForSaleFairValueDisclosure_a117f397-d5ad-4209-812c-e9dab9b689ca" xlink:href="cfb-20210630.xsd#cfb_RepossessedAssetsHeldForSaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:to="loc_cfb_RepossessedAssetsHeldForSaleFairValueDisclosure_a117f397-d5ad-4209-812c-e9dab9b689ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_ForeclosedAssetsHeldForSaleMeasurementInput_7db2a4d3-a70b-4478-97e0-0d248587ddcc" xlink:href="cfb-20210630.xsd#cfb_ForeclosedAssetsHeldForSaleMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:to="loc_cfb_ForeclosedAssetsHeldForSaleMeasurementInput_7db2a4d3-a70b-4478-97e0-0d248587ddcc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ea8836f5-0b9d-4f7c-baf5-b189d8cb4c4c" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a7afb104-635b-4d4b-81f3-d1e4f0744e26" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a7afb104-635b-4d4b-81f3-d1e4f0744e26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a7afb104-635b-4d4b-81f3-d1e4f0744e26_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a7afb104-635b-4d4b-81f3-d1e4f0744e26" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a7afb104-635b-4d4b-81f3-d1e4f0744e26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_216a089b-fd47-4fc3-a35e-bbc491c7562d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a7afb104-635b-4d4b-81f3-d1e4f0744e26" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_216a089b-fd47-4fc3-a35e-bbc491c7562d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_6e02d049-5aec-4ce4-8e9d-870e7c084de3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_216a089b-fd47-4fc3-a35e-bbc491c7562d" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_6e02d049-5aec-4ce4-8e9d-870e7c084de3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_385cc38a-4cc3-49dc-837d-badfc91c8841" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_385cc38a-4cc3-49dc-837d-badfc91c8841" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_385cc38a-4cc3-49dc-837d-badfc91c8841_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_385cc38a-4cc3-49dc-837d-badfc91c8841" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_385cc38a-4cc3-49dc-837d-badfc91c8841_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_e118b7aa-0812-4b8f-b14a-ecd2b6e93020" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_385cc38a-4cc3-49dc-837d-badfc91c8841" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_e118b7aa-0812-4b8f-b14a-ecd2b6e93020" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_2a237def-5923-493d-8fbd-e7de9864aa7f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_e118b7aa-0812-4b8f-b14a-ecd2b6e93020" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_2a237def-5923-493d-8fbd-e7de9864aa7f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_e445efa9-e0eb-4791-a176-09b05b95d808" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:to="loc_us-gaap_ValuationTechniqueAxis_e445efa9-e0eb-4791-a176-09b05b95d808" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_e445efa9-e0eb-4791-a176-09b05b95d808_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_e445efa9-e0eb-4791-a176-09b05b95d808" xlink:to="loc_us-gaap_ValuationTechniqueDomain_e445efa9-e0eb-4791-a176-09b05b95d808_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_03930679-0dd1-456a-90cf-7560601c9c96" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_e445efa9-e0eb-4791-a176-09b05b95d808" xlink:to="loc_us-gaap_ValuationTechniqueDomain_03930679-0dd1-456a-90cf-7560601c9c96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_ca4f9f39-0416-4d6e-9159-7a72c7ed0459" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_03930679-0dd1-456a-90cf-7560601c9c96" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_ca4f9f39-0416-4d6e-9159-7a72c7ed0459" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_3dff6a4c-620e-4409-b262-f5ed57f49e2c" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:to="loc_srt_RangeAxis_3dff6a4c-620e-4409-b262-f5ed57f49e2c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_3dff6a4c-620e-4409-b262-f5ed57f49e2c_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_3dff6a4c-620e-4409-b262-f5ed57f49e2c" xlink:to="loc_srt_RangeMember_3dff6a4c-620e-4409-b262-f5ed57f49e2c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_271d5139-18e1-43a4-8a63-b4e8f05be32b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_3dff6a4c-620e-4409-b262-f5ed57f49e2c" xlink:to="loc_srt_RangeMember_271d5139-18e1-43a4-8a63-b4e8f05be32b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_6aaa1fde-fce4-4390-9bc9-8e87eb2a19c8" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_271d5139-18e1-43a4-8a63-b4e8f05be32b" xlink:to="loc_srt_MinimumMember_6aaa1fde-fce4-4390-9bc9-8e87eb2a19c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_57175ec6-be75-44e5-8fa6-0ea8be5aeca9" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_271d5139-18e1-43a4-8a63-b4e8f05be32b" xlink:to="loc_srt_MaximumMember_57175ec6-be75-44e5-8fa6-0ea8be5aeca9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_1b27a4af-2b75-4f16-a84d-ba88ca5325c1" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_271d5139-18e1-43a4-8a63-b4e8f05be32b" xlink:to="loc_srt_WeightedAverageMember_1b27a4af-2b75-4f16-a84d-ba88ca5325c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_43f3bcf6-ac59-47d5-bb6c-f3615976c417" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_52d94c00-7445-4243-b83d-c117efc03f67" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_43f3bcf6-ac59-47d5-bb6c-f3615976c417" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_43f3bcf6-ac59-47d5-bb6c-f3615976c417_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_43f3bcf6-ac59-47d5-bb6c-f3615976c417" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_43f3bcf6-ac59-47d5-bb6c-f3615976c417_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_88d5140c-ae02-4b9f-bef9-252da9817cbb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_43f3bcf6-ac59-47d5-bb6c-f3615976c417" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_88d5140c-ae02-4b9f-bef9-252da9817cbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_e029c970-58bb-4a12-a1ff-cd9493474e83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_88d5140c-ae02-4b9f-bef9-252da9817cbb" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_e029c970-58bb-4a12-a1ff-cd9493474e83" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsFairValueofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#DisclosuresaboutFairValueofFinancialInstrumentsFairValueofFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/DisclosuresaboutFairValueofFinancialInstrumentsFairValueofFinancialInstrumentsDetails" xlink:type="extended" id="i0e518b8072a343f68b8de201db01d499_DisclosuresaboutFairValueofFinancialInstrumentsFairValueofFinancialInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_d68bc901-42bc-429a-bcf8-1304dc69db3a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_d68bc901-42bc-429a-bcf8-1304dc69db3a" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_4ffdfa3f-947b-415c-b1cc-87b4976c2977" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_4ffdfa3f-947b-415c-b1cc-87b4976c2977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_75303653-f89a-4361-b0b2-6e7e530acbac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_75303653-f89a-4361-b0b2-6e7e530acbac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableFairValueDisclosure_785ed4ba-a9c3-4a4a-b908-a90935e11960" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoansReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_LoansReceivableFairValueDisclosure_785ed4ba-a9c3-4a4a-b908-a90935e11960" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiRestricted_85c25ddb-059f-47ec-9e05-2ed5c4e1a869" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquitySecuritiesFvNiRestricted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_EquitySecuritiesFvNiRestricted_85c25ddb-059f-47ec-9e05-2ed5c4e1a869" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_InterestReceivableFairValueDisclosure_74f5c907-0813-4692-a0a4-7f4768a68e7e" xlink:href="cfb-20210630.xsd#cfb_InterestReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_cfb_InterestReceivableFairValueDisclosure_74f5c907-0813-4692-a0a4-7f4768a68e7e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_67ff7b28-faad-4849-b9af-68c7548e71b5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquitySecuritiesFvNi"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_67ff7b28-faad-4849-b9af-68c7548e71b5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_43fee237-ce5f-4c7e-9f2d-750a47c7eb6f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_DerivativeAssets_43fee237-ce5f-4c7e-9f2d-750a47c7eb6f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_87ff3fe2-785b-4abb-9391-ac0d82542605" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_847f2ae5-cfd0-4ba6-89cc-b462e85a86a3" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_87ff3fe2-785b-4abb-9391-ac0d82542605" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_d68bc901-42bc-429a-bcf8-1304dc69db3a" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsFairValueDisclosure_45960275-91a8-4462-8c7a-49a938127842" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepositsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_us-gaap_DepositsFairValueDisclosure_45960275-91a8-4462-8c7a-49a938127842" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsPurchasedAndSecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure_2746ae11-501b-4fdc-8517-66bfcbbdedfd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalFundsPurchasedAndSecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_us-gaap_FederalFundsPurchasedAndSecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure_2746ae11-501b-4fdc-8517-66bfcbbdedfd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure_f664707e-1255-4cbd-8ffa-80f6df7a9cc8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure_f664707e-1255-4cbd-8ffa-80f6df7a9cc8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_OtherBorrowingsFairValueDisclosure_b5632c67-cf04-41f0-95c0-4914f6d59ac1" xlink:href="cfb-20210630.xsd#cfb_OtherBorrowingsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_cfb_OtherBorrowingsFairValueDisclosure_b5632c67-cf04-41f0-95c0-4914f6d59ac1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cfb_InterestPayableFairValueDisclosure_7b264ea5-0f9d-47db-b045-65d7412a0758" xlink:href="cfb-20210630.xsd#cfb_InterestPayableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_cfb_InterestPayableFairValueDisclosure_7b264ea5-0f9d-47db-b045-65d7412a0758" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_d262d77e-a7df-476d-814a-fc4a01157579" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_us-gaap_DerivativeLiabilities_d262d77e-a7df-476d-814a-fc4a01157579" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_6817e3a8-265d-43a6-99f1-6381aa73673b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialLiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_e9210e9d-9c6c-4bb3-befc-1d2bdf0bdd41" xlink:to="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_6817e3a8-265d-43a6-99f1-6381aa73673b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88c92f6a-0242-4788-815d-faf23b258faf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_d68bc901-42bc-429a-bcf8-1304dc69db3a" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88c92f6a-0242-4788-815d-faf23b258faf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_6f43c755-5e92-4bfc-95de-5e27573c7645" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88c92f6a-0242-4788-815d-faf23b258faf" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_6f43c755-5e92-4bfc-95de-5e27573c7645" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6f43c755-5e92-4bfc-95de-5e27573c7645_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_6f43c755-5e92-4bfc-95de-5e27573c7645" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6f43c755-5e92-4bfc-95de-5e27573c7645_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_86d1a2ec-0439-47ba-b482-1d5e0b97bed7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_6f43c755-5e92-4bfc-95de-5e27573c7645" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_86d1a2ec-0439-47ba-b482-1d5e0b97bed7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a8d66dbb-6ddf-4759-977c-c4939448f79c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_86d1a2ec-0439-47ba-b482-1d5e0b97bed7" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a8d66dbb-6ddf-4759-977c-c4939448f79c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_278779bc-0a73-4c87-8a6e-56325bdc315a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_86d1a2ec-0439-47ba-b482-1d5e0b97bed7" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_278779bc-0a73-4c87-8a6e-56325bdc315a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_b590f73c-44a7-4c05-bbc3-ba2a514995eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_86d1a2ec-0439-47ba-b482-1d5e0b97bed7" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_b590f73c-44a7-4c05-bbc3-ba2a514995eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_503b9595-d936-43e2-b77d-ae9fec9fae65" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88c92f6a-0242-4788-815d-faf23b258faf" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_503b9595-d936-43e2-b77d-ae9fec9fae65" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_503b9595-d936-43e2-b77d-ae9fec9fae65_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_503b9595-d936-43e2-b77d-ae9fec9fae65" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_503b9595-d936-43e2-b77d-ae9fec9fae65_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_32f8ced2-153f-4ccf-b902-94cd9be09d0c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_503b9595-d936-43e2-b77d-ae9fec9fae65" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_32f8ced2-153f-4ccf-b902-94cd9be09d0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_7ed0c382-578f-450b-9fec-cd040231141e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_32f8ced2-153f-4ccf-b902-94cd9be09d0c" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_7ed0c382-578f-450b-9fec-cd040231141e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_7241f096-f4f7-43ad-959b-22e20039b08b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_32f8ced2-153f-4ccf-b902-94cd9be09d0c" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_7241f096-f4f7-43ad-959b-22e20039b08b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_24020bf8-3400-4495-8881-41ba6cc117a4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_32f8ced2-153f-4ccf-b902-94cd9be09d0c" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_24020bf8-3400-4495-8881-41ba6cc117a4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.crossfirstbank.com/role/CommitmentsandCreditRiskDetails" xlink:type="simple" xlink:href="cfb-20210630.xsd#CommitmentsandCreditRiskDetails"/>
  <link:definitionLink xlink:role="http://www.crossfirstbank.com/role/CommitmentsandCreditRiskDetails" xlink:type="extended" id="ic0c78d82cd1d4ea1b68ba638dcefe917_CommitmentsandCreditRiskDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_16dd877b-4970-4cc6-8bce-4bcf2ad65b40" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability_e3daf8a3-8562-46d2-a43b-36ad570e9e75" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_16dd877b-4970-4cc6-8bce-4bcf2ad65b40" xlink:to="loc_us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability_e3daf8a3-8562-46d2-a43b-36ad570e9e75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_28732352-2446-4e26-a169-3c88b71bc3f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_16dd877b-4970-4cc6-8bce-4bcf2ad65b40" xlink:to="loc_us-gaap_LossContingenciesTable_28732352-2446-4e26-a169-3c88b71bc3f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_28732352-2446-4e26-a169-3c88b71bc3f0" xlink:to="loc_us-gaap_FinancialInstrumentAxis_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_91636a39-c36c-4023-aad1-834eb28e31da" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d9836f9e-d8c7-4620-b0c9-0460c53cbf9b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_91636a39-c36c-4023-aad1-834eb28e31da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanOriginationCommitmentsMember_55ef4fab-7ec5-4974-a1a3-6d67234e4e1d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoanOriginationCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_91636a39-c36c-4023-aad1-834eb28e31da" xlink:to="loc_us-gaap_LoanOriginationCommitmentsMember_55ef4fab-7ec5-4974-a1a3-6d67234e4e1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_d0c9280e-0f0f-4269-b861-a924dbbb65ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_91636a39-c36c-4023-aad1-834eb28e31da" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_d0c9280e-0f0f-4269-b861-a924dbbb65ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_e328af46-4e56-46a1-9181-55dbfc548c06" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_91636a39-c36c-4023-aad1-834eb28e31da" xlink:to="loc_us-gaap_LineOfCreditMember_e328af46-4e56-46a1-9181-55dbfc548c06" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
