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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:c4019caa-291d-4920-aee6-81f50e1b248f,g:4dc47052-0a4e-47f9-a744-2af9feda3b13-->
<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.bannerbank.com/role/Cover" xlink:type="simple" xlink:href="banr-20250916.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.bannerbank.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_3c6a6313-696a-41a6-85b1-85a96f5311f0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_DocumentInformationTable_3c6a6313-696a-41a6-85b1-85a96f5311f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationDocumentAxis_17f9788b-1850-46cf-9452-33f72f9e88fe" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationDocumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_3c6a6313-696a-41a6-85b1-85a96f5311f0" xlink:to="loc_dei_DocumentInformationDocumentAxis_17f9788b-1850-46cf-9452-33f72f9e88fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_17f9788b-1850-46cf-9452-33f72f9e88fe_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_DocumentInformationDocumentAxis_17f9788b-1850-46cf-9452-33f72f9e88fe" xlink:to="loc_dei_DocumentDomain_17f9788b-1850-46cf-9452-33f72f9e88fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_4e16236b-3f3c-4ec7-9928-584c0e3a6db3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_DocumentInformationDocumentAxis_17f9788b-1850-46cf-9452-33f72f9e88fe" xlink:to="loc_dei_DocumentDomain_4e16236b-3f3c-4ec7-9928-584c0e3a6db3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_9b4a0418-2717-4860-927f-84ef8efa5e38" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_DocumentType_9b4a0418-2717-4860-927f-84ef8efa5e38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_7778383e-a37a-4c5f-966f-41200afefd93" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_DocumentPeriodEndDate_7778383e-a37a-4c5f-966f-41200afefd93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_71d646b2-52fc-4837-9745-c3a33d5c1186" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityRegistrantName_71d646b2-52fc-4837-9745-c3a33d5c1186" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_b16869fc-23e1-4529-966c-e2a4df8bcd46" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityIncorporationStateCountryCode_b16869fc-23e1-4529-966c-e2a4df8bcd46" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_b0235a5d-cb2f-4269-aa1e-cb576b942e15" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityFileNumber_b0235a5d-cb2f-4269-aa1e-cb576b942e15" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_9c85e6db-0c1d-4048-b4af-6836303b4f5b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityTaxIdentificationNumber_9c85e6db-0c1d-4048-b4af-6836303b4f5b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_2f6a6226-49db-45a9-89c8-0c8116e27bfb" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityAddressAddressLine1_2f6a6226-49db-45a9-89c8-0c8116e27bfb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_8f7b685a-2060-4562-bf53-73a6415d39ea" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityAddressCityOrTown_8f7b685a-2060-4562-bf53-73a6415d39ea" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_ae273e63-7ae6-4431-bf69-82a6cc3ec5c8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityAddressStateOrProvince_ae273e63-7ae6-4431-bf69-82a6cc3ec5c8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_bb6ff650-0a96-45b1-a5c7-38e3538b243e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityAddressPostalZipCode_bb6ff650-0a96-45b1-a5c7-38e3538b243e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_bae6070c-a874-4a9e-87c7-91b4f78cd23f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_CityAreaCode_bae6070c-a874-4a9e-87c7-91b4f78cd23f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_229f8c2d-5a4e-4a12-b800-c012f329dfaf" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_LocalPhoneNumber_229f8c2d-5a4e-4a12-b800-c012f329dfaf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_8dda203b-f093-4f45-957e-26e1b837fd07" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_WrittenCommunications"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_WrittenCommunications_8dda203b-f093-4f45-957e-26e1b837fd07" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_d2ddb3bf-4f36-4367-9605-0e14d9c18c71" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SolicitingMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_SolicitingMaterial_d2ddb3bf-4f36-4367-9605-0e14d9c18c71" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_9df13289-9cbe-4ab4-8f53-771b10151260" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_PreCommencementTenderOffer_9df13289-9cbe-4ab4-8f53-771b10151260" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_ca97672c-51b8-4e62-84b4-7696d6fe15bd" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_ca97672c-51b8-4e62-84b4-7696d6fe15bd" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_200d1f5b-e7e7-4c6e-a7a7-a28457b525f1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_Security12bTitle_200d1f5b-e7e7-4c6e-a7a7-a28457b525f1" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_ec4f918b-9ff2-41e1-8bf8-b092f36f00b4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_TradingSymbol_ec4f918b-9ff2-41e1-8bf8-b092f36f00b4" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_178e53f5-68e6-4bae-b9a4-45f0f4dd6344" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_SecurityExchangeName_178e53f5-68e6-4bae-b9a4-45f0f4dd6344" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_abf5387b-8e97-42ae-95d2-a0266704b352" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityEmergingGrowthCompany_abf5387b-8e97-42ae-95d2-a0266704b352" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_c7fe0616-0bac-4549-8485-06f8d0043b99" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_EntityCentralIndexKey_c7fe0616-0bac-4549-8485-06f8d0043b99" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_99054b83-618a-488d-915f-617ad4c31d7f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_02341564-9276-452c-8efc-9d43b4d77c9e" xlink:to="loc_dei_AmendmentFlag_99054b83-618a-488d-915f-617ad4c31d7f" xlink:type="arc" order="21"/>
  </link:definitionLink>
</link:linkbase>
