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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:0c44629d-ddf1-45b2-a144-1d580fb85c7c,g:6806550f-8f5d-4286-837b-587d606d2d21-->
<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.sjwater.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="sjw-20250331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_c06ca673-57f4-4dca-a48c-24e7d4bb8d8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_5d325b57-ae00-4bec-81bc-21d30e2426b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_c06ca673-57f4-4dca-a48c-24e7d4bb8d8b" xlink:to="loc_us-gaap_StatementTable_5d325b57-ae00-4bec-81bc-21d30e2426b1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3ed58fff-f0ac-44a0-b11c-5379b6e0d202" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5d325b57-ae00-4bec-81bc-21d30e2426b1" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3ed58fff-f0ac-44a0-b11c-5379b6e0d202" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3ed58fff-f0ac-44a0-b11c-5379b6e0d202_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3ed58fff-f0ac-44a0-b11c-5379b6e0d202" xlink:to="loc_us-gaap_EquityComponentDomain_3ed58fff-f0ac-44a0-b11c-5379b6e0d202_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3ed58fff-f0ac-44a0-b11c-5379b6e0d202" xlink:to="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_e595b497-2d79-43b0-97bf-6d13bf056888" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:to="loc_us-gaap_CommonStockMember_e595b497-2d79-43b0-97bf-6d13bf056888" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_8b50ed6f-fdbf-4835-b500-93eb49fae5bd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_8b50ed6f-fdbf-4835-b500-93eb49fae5bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_ec777d72-8a05-4e29-925b-b320b884c50b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:to="loc_us-gaap_RetainedEarningsMember_ec777d72-8a05-4e29-925b-b320b884c50b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_820489ed-d355-4ba6-9c2c-99a4ee9ce4e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5d002208-68b2-4c0f-8684-76a95891c156" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_820489ed-d355-4ba6-9c2c-99a4ee9ce4e9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c06ca673-57f4-4dca-a48c-24e7d4bb8d8b" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_35613977-8ce0-4f27-a0f0-b37ad773cc8a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_35613977-8ce0-4f27-a0f0-b37ad773cc8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_80d8ae98-3c52-4dbe-84d6-59ee9a88e0ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockholdersEquity_80d8ae98-3c52-4dbe-84d6-59ee9a88e0ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_1d48011f-5674-485c-8e05-bce209e33c58" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_NetIncomeLoss_1d48011f-5674-485c-8e05-bce209e33c58" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_ed88f673-467d-4dd5-86a6-0a673121f5fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_ed88f673-467d-4dd5-86a6-0a673121f5fc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_fcd10f76-ed71-4fa8-8621-f43cf90a868c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_fcd10f76-ed71-4fa8-8621-f43cf90a868c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_c8073270-fd09-4404-a8fa-3c89c5b813f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_c8073270-fd09-4404-a8fa-3c89c5b813f2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_23e1d9fb-ad92-4d45-b234-2a59e69baf1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_23e1d9fb-ad92-4d45-b234-2a59e69baf1a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_36ee0aaf-1caf-4dcf-802a-6270d93fb54f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_36ee0aaf-1caf-4dcf-802a-6270d93fb54f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_052277a1-3edd-45b0-af0e-6094d556503f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_052277a1-3edd-45b0-af0e-6094d556503f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_eec1702e-5ebb-46be-844a-6519b28706cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_eec1702e-5ebb-46be-844a-6519b28706cb" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_31d4735b-6d32-429a-8727-1524c42ce670" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_31d4735b-6d32-429a-8727-1524c42ce670" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Dividends_be4c8bdd-7052-476d-93cc-f9ad08205ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Dividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ed203a0f-490e-48b3-b7d6-5e0803017046" xlink:to="loc_us-gaap_Dividends_be4c8bdd-7052-476d-93cc-f9ad08205ca3" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_6e097151-e014-409a-a78d-51751573dab0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_faea5c47-08ec-4564-be07-7d52d79ef2a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/GeneralFairValueMeasurementDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#GeneralFairValueMeasurementDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/GeneralFairValueMeasurementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_54468ec6-1496-403a-bf3d-d7ff26c23cef" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_013148e5-e85c-4a0f-a95f-be3c2ba3b1b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_54468ec6-1496-403a-bf3d-d7ff26c23cef" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_013148e5-e85c-4a0f-a95f-be3c2ba3b1b4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4980b1ad-4f1b-43ac-b199-b8f2c9934804" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_013148e5-e85c-4a0f-a95f-be3c2ba3b1b4" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4980b1ad-4f1b-43ac-b199-b8f2c9934804" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4980b1ad-4f1b-43ac-b199-b8f2c9934804_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4980b1ad-4f1b-43ac-b199-b8f2c9934804" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4980b1ad-4f1b-43ac-b199-b8f2c9934804_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2086761-a3fa-4c3c-84f8-6704b454baa6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4980b1ad-4f1b-43ac-b199-b8f2c9934804" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2086761-a3fa-4c3c-84f8-6704b454baa6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_7051446f-128c-4a45-a21d-4bdfc1ca3c6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2086761-a3fa-4c3c-84f8-6704b454baa6" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_7051446f-128c-4a45-a21d-4bdfc1ca3c6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_d898fd3a-9eeb-452b-b25d-67140a14a713" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2086761-a3fa-4c3c-84f8-6704b454baa6" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_d898fd3a-9eeb-452b-b25d-67140a14a713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_d03ea2c8-4c9d-4141-a689-900d2a402d57" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2086761-a3fa-4c3c-84f8-6704b454baa6" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_d03ea2c8-4c9d-4141-a689-900d2a402d57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_801b2dde-9f90-42d4-9051-5474463714f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_013148e5-e85c-4a0f-a95f-be3c2ba3b1b4" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_801b2dde-9f90-42d4-9051-5474463714f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_801b2dde-9f90-42d4-9051-5474463714f5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_801b2dde-9f90-42d4-9051-5474463714f5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_801b2dde-9f90-42d4-9051-5474463714f5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_458fd8b2-4aae-49d4-975a-97b28737a4ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_801b2dde-9f90-42d4-9051-5474463714f5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_458fd8b2-4aae-49d4-975a-97b28737a4ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_aaa77014-289e-4a8c-9875-1bb8859d1af4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_458fd8b2-4aae-49d4-975a-97b28737a4ec" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_aaa77014-289e-4a8c-9875-1bb8859d1af4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_68bb41c5-8997-4798-92ce-f805af3e5593" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_54468ec6-1496-403a-bf3d-d7ff26c23cef" xlink:to="loc_us-gaap_LongTermDebtFairValue_68bb41c5-8997-4798-92ce-f805af3e5593" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_9ece628f-9199-49e4-bc42-ddc55e374095" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_54468ec6-1496-403a-bf3d-d7ff26c23cef" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_9ece628f-9199-49e4-bc42-ddc55e374095" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/GeneralEarningsperShareDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#GeneralEarningsperShareDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/GeneralEarningsperShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_cfd4a0a2-b681-43c4-9f82-d260fd0a1315" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f4b3864d-b15e-4cc9-b4d8-94a46a529e11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_cfd4a0a2-b681-43c4-9f82-d260fd0a1315" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f4b3864d-b15e-4cc9-b4d8-94a46a529e11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_a59ba71f-7504-46f0-8a5e-44273d0a5fac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f4b3864d-b15e-4cc9-b4d8-94a46a529e11" xlink:to="loc_us-gaap_StatementClassOfStockAxis_a59ba71f-7504-46f0-8a5e-44273d0a5fac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a59ba71f-7504-46f0-8a5e-44273d0a5fac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a59ba71f-7504-46f0-8a5e-44273d0a5fac" xlink:to="loc_us-gaap_ClassOfStockDomain_a59ba71f-7504-46f0-8a5e-44273d0a5fac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_9cc51a0e-9fe2-430f-bff8-9202234be7cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a59ba71f-7504-46f0-8a5e-44273d0a5fac" xlink:to="loc_us-gaap_ClassOfStockDomain_9cc51a0e-9fe2-430f-bff8-9202234be7cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_99e0d94f-6b8f-4358-912b-d8902afac80d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_9cc51a0e-9fe2-430f-bff8-9202234be7cd" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_99e0d94f-6b8f-4358-912b-d8902afac80d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7863ddf2-3f8f-4b5f-9e00-d76ee7fdd680" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_cfd4a0a2-b681-43c4-9f82-d260fd0a1315" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7863ddf2-3f8f-4b5f-9e00-d76ee7fdd680" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/RegulatoryMattersRegulatoryAssetsNetDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#RegulatoryMattersRegulatoryAssetsNetDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/RegulatoryMattersRegulatoryAssetsNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetLineItems_08cdc47e-7edf-477c-9ac5-85cedefd733b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRegulatoryAssetsTable_babddee7-8b8c-4670-8afa-1e4a8af77770" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRegulatoryAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RegulatoryAssetLineItems_08cdc47e-7edf-477c-9ac5-85cedefd733b" xlink:to="loc_us-gaap_ScheduleOfRegulatoryAssetsTable_babddee7-8b8c-4670-8afa-1e4a8af77770" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetAxis_c4731da3-fab0-4ff6-9fa8-5571a9c24358" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRegulatoryAssetsTable_babddee7-8b8c-4670-8afa-1e4a8af77770" xlink:to="loc_us-gaap_RegulatoryAssetAxis_c4731da3-fab0-4ff6-9fa8-5571a9c24358" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetDomain_c4731da3-fab0-4ff6-9fa8-5571a9c24358_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RegulatoryAssetAxis_c4731da3-fab0-4ff6-9fa8-5571a9c24358" xlink:to="loc_us-gaap_RegulatoryAssetDomain_c4731da3-fab0-4ff6-9fa8-5571a9c24358_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RegulatoryAssetAxis_c4731da3-fab0-4ff6-9fa8-5571a9c24358" xlink:to="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxChargesMember_267fc019-c3b9-42df-b3ae-7cb6a85bcf62" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredIncomeTaxChargesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_us-gaap_DeferredIncomeTaxChargesMember_267fc019-c3b9-42df-b3ae-7cb6a85bcf62" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_MontereyWaterRevenueAdjustmentMechanismMWRAMMember_4750f835-e965-4692-b709-c0628a5ac69f" xlink:href="sjw-20250331.xsd#sjw_MontereyWaterRevenueAdjustmentMechanismMWRAMMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_MontereyWaterRevenueAdjustmentMechanismMWRAMMember_4750f835-e965-4692-b709-c0628a5ac69f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_BusinessCombinationsDebtPremiumMember_7321c8f7-1f4c-4257-89cb-7fa280de182c" xlink:href="sjw-20250331.xsd#sjw_BusinessCombinationsDebtPremiumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_BusinessCombinationsDebtPremiumMember_7321c8f7-1f4c-4257-89cb-7fa280de182c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_EmployeeBenefitCostsMember_1d89810d-e4f6-411e-ae29-ce366eb14db0" xlink:href="sjw-20250331.xsd#sjw_EmployeeBenefitCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_EmployeeBenefitCostsMember_1d89810d-e4f6-411e-ae29-ce366eb14db0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_RevenueAdjustmentMechanismsMember_06299018-8ff8-4f90-a2d2-af92a1a2a475" xlink:href="sjw-20250331.xsd#sjw_RevenueAdjustmentMechanismsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_RevenueAdjustmentMechanismsMember_06299018-8ff8-4f90-a2d2-af92a1a2a475" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_CustomerAssistanceProgramBalancingAccountMember_cd68b485-dbb5-4670-a52a-0353c54c5e9c" xlink:href="sjw-20250331.xsd#sjw_CustomerAssistanceProgramBalancingAccountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_CustomerAssistanceProgramBalancingAccountMember_cd68b485-dbb5-4670-a52a-0353c54c5e9c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_A2022GeneralRateCaseInterimMemorandumAccountMember_3cd500cf-ccb7-4382-a60d-51c1691bcc50" xlink:href="sjw-20250331.xsd#sjw_A2022GeneralRateCaseInterimMemorandumAccountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_A2022GeneralRateCaseInterimMemorandumAccountMember_3cd500cf-ccb7-4382-a60d-51c1691bcc50" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementPlansCostsMember_0d64d898-ae5e-4db2-86aa-4bf73692723f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementPlansCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_us-gaap_PensionAndOtherPostretirementPlansCostsMember_0d64d898-ae5e-4db2-86aa-4bf73692723f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_OtherRegulatoryAssetsMember_09138bc4-8921-4cee-b05d-aa589c0abb91" xlink:href="sjw-20250331.xsd#sjw_OtherRegulatoryAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetDomain_389e3360-7491-4752-a75f-95536fd46952" xlink:to="loc_sjw_OtherRegulatoryAssetsMember_09138bc4-8921-4cee-b05d-aa589c0abb91" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityAxis_118fae2d-90d8-41e4-8a21-f1fd21fac632" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRegulatoryAssetsTable_babddee7-8b8c-4670-8afa-1e4a8af77770" xlink:to="loc_us-gaap_RegulatoryLiabilityAxis_118fae2d-90d8-41e4-8a21-f1fd21fac632" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityDomain_118fae2d-90d8-41e4-8a21-f1fd21fac632_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RegulatoryLiabilityAxis_118fae2d-90d8-41e4-8a21-f1fd21fac632" xlink:to="loc_us-gaap_RegulatoryLiabilityDomain_118fae2d-90d8-41e4-8a21-f1fd21fac632_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RegulatoryLiabilityAxis_118fae2d-90d8-41e4-8a21-f1fd21fac632" xlink:to="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_CostOfRemovalMember_ea1ba154-d5e2-4c96-adb8-133c25e25571" xlink:href="sjw-20250331.xsd#sjw_CostOfRemovalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_CostOfRemovalMember_ea1ba154-d5e2-4c96-adb8-133c25e25571" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxChargesMember_8119e456-0c33-48f9-a6e0-8b4b6b037d31" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredIncomeTaxChargesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_us-gaap_DeferredIncomeTaxChargesMember_8119e456-0c33-48f9-a6e0-8b4b6b037d31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_UnrecognizedPensionsAndOtherPostretirementBenefitsMember_739c07cb-8701-4e8d-8498-a3059952796f" xlink:href="sjw-20250331.xsd#sjw_UnrecognizedPensionsAndOtherPostretirementBenefitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_UnrecognizedPensionsAndOtherPostretirementBenefitsMember_739c07cb-8701-4e8d-8498-a3059952796f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_WaterSupplyCostsMember_6a8cd99b-5547-46ae-9a88-d114d8c1236c" xlink:href="sjw-20250331.xsd#sjw_WaterSupplyCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_WaterSupplyCostsMember_6a8cd99b-5547-46ae-9a88-d114d8c1236c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_EmployeeBenefitCostsMember_b026971e-70bc-41cf-8f5e-3c6ae72268c7" xlink:href="sjw-20250331.xsd#sjw_EmployeeBenefitCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_EmployeeBenefitCostsMember_b026971e-70bc-41cf-8f5e-3c6ae72268c7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_RevenueAdjustmentMechanismsMember_59ddf770-def3-4c7d-addd-f5c05ab8494c" xlink:href="sjw-20250331.xsd#sjw_RevenueAdjustmentMechanismsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_RevenueAdjustmentMechanismsMember_59ddf770-def3-4c7d-addd-f5c05ab8494c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_OtherRegulatoryLiabilitiesMember_026b755c-2b20-45ce-85cb-2527108a7365" xlink:href="sjw-20250331.xsd#sjw_OtherRegulatoryLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilityDomain_5ff91a79-3692-4a08-96d2-41356b85eddf" xlink:to="loc_sjw_OtherRegulatoryLiabilitiesMember_026b755c-2b20-45ce-85cb-2527108a7365" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6f09ee91-7a8b-4d25-851d-a77ccc8b7443" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRegulatoryAssetsTable_babddee7-8b8c-4670-8afa-1e4a8af77770" xlink:to="loc_srt_RangeAxis_6f09ee91-7a8b-4d25-851d-a77ccc8b7443" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6f09ee91-7a8b-4d25-851d-a77ccc8b7443_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6f09ee91-7a8b-4d25-851d-a77ccc8b7443" xlink:to="loc_srt_RangeMember_6f09ee91-7a8b-4d25-851d-a77ccc8b7443_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_60cf4760-972d-46c5-8a30-78661e0c8dac" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6f09ee91-7a8b-4d25-851d-a77ccc8b7443" xlink:to="loc_srt_RangeMember_60cf4760-972d-46c5-8a30-78661e0c8dac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_32cf06e8-26c8-452a-a4b1-295ab83b1bbc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_60cf4760-972d-46c5-8a30-78661e0c8dac" xlink:to="loc_srt_MinimumMember_32cf06e8-26c8-452a-a4b1-295ab83b1bbc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_e08a0a9a-ce34-44ae-af9a-7fcd051aa53f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_60cf4760-972d-46c5-8a30-78661e0c8dac" xlink:to="loc_srt_MaximumMember_e08a0a9a-ce34-44ae-af9a-7fcd051aa53f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetRegulatoryAssetsAbstract_d4f39792-938b-438e-96ed-4d6962fd0673" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetRegulatoryAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetLineItems_08cdc47e-7edf-477c-9ac5-85cedefd733b" xlink:to="loc_us-gaap_NetRegulatoryAssetsAbstract_d4f39792-938b-438e-96ed-4d6962fd0673" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssets_3461763a-c763-48c3-ad60-e84ddcb932fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetRegulatoryAssetsAbstract_d4f39792-938b-438e-96ed-4d6962fd0673" xlink:to="loc_us-gaap_RegulatoryAssets_3461763a-c763-48c3-ad60-e84ddcb932fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetsCurrent_1a8ed58c-2179-47ce-899a-991055dd4e56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetRegulatoryAssetsAbstract_d4f39792-938b-438e-96ed-4d6962fd0673" xlink:to="loc_us-gaap_RegulatoryAssetsCurrent_1a8ed58c-2179-47ce-899a-991055dd4e56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetsNoncurrent_e91124cf-2806-41c9-8cb8-98051e1139fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetRegulatoryAssetsAbstract_d4f39792-938b-438e-96ed-4d6962fd0673" xlink:to="loc_us-gaap_RegulatoryAssetsNoncurrent_e91124cf-2806-41c9-8cb8-98051e1139fe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommonUsefulLife_3491d4af-1301-4340-a61b-349397a975ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommonUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetLineItems_08cdc47e-7edf-477c-9ac5-85cedefd733b" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommonUsefulLife_3491d4af-1301-4340-a61b-349397a975ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_NetRegulatoryLiabilitiesAbstract_5cfd96b8-bd04-402c-80f3-f4cbd2b05230" xlink:href="sjw-20250331.xsd#sjw_NetRegulatoryLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAssetLineItems_08cdc47e-7edf-477c-9ac5-85cedefd733b" xlink:to="loc_sjw_NetRegulatoryLiabilitiesAbstract_5cfd96b8-bd04-402c-80f3-f4cbd2b05230" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilities_0b93b07d-ae03-47a5-a7fb-2f733730fbaa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sjw_NetRegulatoryLiabilitiesAbstract_5cfd96b8-bd04-402c-80f3-f4cbd2b05230" xlink:to="loc_us-gaap_RegulatoryLiabilities_0b93b07d-ae03-47a5-a7fb-2f733730fbaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityCurrent_bfe13f00-8dce-4a67-bde9-9be9c1bacf27" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sjw_NetRegulatoryLiabilitiesAbstract_5cfd96b8-bd04-402c-80f3-f4cbd2b05230" xlink:to="loc_us-gaap_RegulatoryLiabilityCurrent_bfe13f00-8dce-4a67-bde9-9be9c1bacf27" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityNoncurrent_7d2d0fc8-1d3e-4588-9adb-c777f2569268" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sjw_NetRegulatoryLiabilitiesAbstract_5cfd96b8-bd04-402c-80f3-f4cbd2b05230" xlink:to="loc_us-gaap_RegulatoryLiabilityNoncurrent_7d2d0fc8-1d3e-4588-9adb-c777f2569268" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/CapitalizationDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#CapitalizationDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/CapitalizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsidiarySaleOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_afae3034-9e88-42b7-88b4-c0ae4f86a31d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_afae3034-9e88-42b7-88b4-c0ae4f86a31d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_7178bd14-e9a9-4ce7-b044-634e48117b75" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_afae3034-9e88-42b7-88b4-c0ae4f86a31d" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_7178bd14-e9a9-4ce7-b044-634e48117b75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_7178bd14-e9a9-4ce7-b044-634e48117b75_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_7178bd14-e9a9-4ce7-b044-634e48117b75" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_7178bd14-e9a9-4ce7-b044-634e48117b75_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bffca958-b148-45d0-ae45-0529750e9f7a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_7178bd14-e9a9-4ce7-b044-634e48117b75" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bffca958-b148-45d0-ae45-0529750e9f7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_AtTheMarketOfferingMember_a1855883-c4e6-4d4f-956b-c5d04d54b032" xlink:href="sjw-20250331.xsd#sjw_AtTheMarketOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bffca958-b148-45d0-ae45-0529750e9f7a" xlink:to="loc_sjw_AtTheMarketOfferingMember_a1855883-c4e6-4d4f-956b-c5d04d54b032" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_0c0a5f16-9d8f-4ba0-868c-8719b4e135f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_0c0a5f16-9d8f-4ba0-868c-8719b4e135f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_SaleOfStockAggregateGrossSalesPrice_36bdbda8-3b74-4ad7-854d-2882a72f54e0" xlink:href="sjw-20250331.xsd#sjw_SaleOfStockAggregateGrossSalesPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_sjw_SaleOfStockAggregateGrossSalesPrice_36bdbda8-3b74-4ad7-854d-2882a72f54e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_08f77e03-fd3e-437f-b950-e3fc1258efac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_08f77e03-fd3e-437f-b950-e3fc1258efac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_SaleOfStockWeightedAveragePricePerShare_bab17d9a-4759-45be-8e59-168bda032d3a" xlink:href="sjw-20250331.xsd#sjw_SaleOfStockWeightedAveragePricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_sjw_SaleOfStockWeightedAveragePricePerShare_bab17d9a-4759-45be-8e59-168bda032d3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_dced43f0-86bc-4916-80de-83d1b580a11b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_dced43f0-86bc-4916-80de-83d1b580a11b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_SaleOfStockTotalEquityDistributionAgreementRemaining_b0e66469-ca59-43d6-8e2e-bb66a26f871c" xlink:href="sjw-20250331.xsd#sjw_SaleOfStockTotalEquityDistributionAgreementRemaining"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_896b2720-9a7e-4996-8ba4-eeffd08e0cd5" xlink:to="loc_sjw_SaleOfStockTotalEquityDistributionAgreementRemaining_b0e66469-ca59-43d6-8e2e-bb66a26f871c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/LinesofCreditandLongTermLiabilitiesDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#LinesofCreditandLongTermLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/LinesofCreditandLongTermLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_f0b24b17-47c6-4c36-be33-480b7a013751" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f0b24b17-47c6-4c36-be33-480b7a013751" xlink:to="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_35782543-5671-424e-8b77-690974038d0a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_35782543-5671-424e-8b77-690974038d0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_35782543-5671-424e-8b77-690974038d0a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_35782543-5671-424e-8b77-690974038d0a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_35782543-5671-424e-8b77-690974038d0a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1b11cc58-bbe6-4dbc-8209-f6650fc765fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_35782543-5671-424e-8b77-690974038d0a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1b11cc58-bbe6-4dbc-8209-f6650fc765fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_31685be0-d5cf-49d6-a683-1d75e0201401" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1b11cc58-bbe6-4dbc-8209-f6650fc765fd" xlink:to="loc_us-gaap_LineOfCreditMember_31685be0-d5cf-49d6-a683-1d75e0201401" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_850e48e5-e84f-4049-92f2-30f2f9b49061" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:to="loc_us-gaap_CreditFacilityAxis_850e48e5-e84f-4049-92f2-30f2f9b49061" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_850e48e5-e84f-4049-92f2-30f2f9b49061_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_850e48e5-e84f-4049-92f2-30f2f9b49061" xlink:to="loc_us-gaap_CreditFacilityDomain_850e48e5-e84f-4049-92f2-30f2f9b49061_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_c4910ffa-f983-47c0-8698-a3b9a81eb8a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_850e48e5-e84f-4049-92f2-30f2f9b49061" xlink:to="loc_us-gaap_CreditFacilityDomain_c4910ffa-f983-47c0-8698-a3b9a81eb8a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_a697b65f-a34a-4885-b32a-13e9c8d32aa9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c4910ffa-f983-47c0-8698-a3b9a81eb8a1" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_a697b65f-a34a-4885-b32a-13e9c8d32aa9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_728792cf-982a-4baa-8653-a70d0bdf0852" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:to="loc_us-gaap_DebtInstrumentAxis_728792cf-982a-4baa-8653-a70d0bdf0852" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_728792cf-982a-4baa-8653-a70d0bdf0852_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_728792cf-982a-4baa-8653-a70d0bdf0852" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_728792cf-982a-4baa-8653-a70d0bdf0852_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cb0e336b-f869-447c-b994-b04e360dd54e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_728792cf-982a-4baa-8653-a70d0bdf0852" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cb0e336b-f869-447c-b994-b04e360dd54e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_CTWSCreditAgreementMaturingAugust2025Member_c1e8e969-fc94-4a0b-8bc0-8585d1f44409" xlink:href="sjw-20250331.xsd#sjw_CTWSCreditAgreementMaturingAugust2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cb0e336b-f869-447c-b994-b04e360dd54e" xlink:to="loc_sjw_CTWSCreditAgreementMaturingAugust2025Member_c1e8e969-fc94-4a0b-8bc0-8585d1f44409" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_280a780d-f1b9-4ae1-8438-2f23d3a7e484" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_16ef74e2-5dea-4e07-9921-d6f4ec006286" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_280a780d-f1b9-4ae1-8438-2f23d3a7e484" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_280a780d-f1b9-4ae1-8438-2f23d3a7e484_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_280a780d-f1b9-4ae1-8438-2f23d3a7e484" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_280a780d-f1b9-4ae1-8438-2f23d3a7e484_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_fe1e7575-9475-4667-a0fe-a3911e1e8e67" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_280a780d-f1b9-4ae1-8438-2f23d3a7e484" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_fe1e7575-9475-4667-a0fe-a3911e1e8e67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_aa291bdd-81b9-4e0c-a8fb-0fdaa6b2688b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_fe1e7575-9475-4667-a0fe-a3911e1e8e67" xlink:to="loc_us-gaap_SubsequentEventMember_aa291bdd-81b9-4e0c-a8fb-0fdaa6b2688b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_2cace724-51c1-4946-8718-ca583adc0872" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f0b24b17-47c6-4c36-be33-480b7a013751" xlink:to="loc_us-gaap_ShortTermDebtWeightedAverageInterestRate_2cace724-51c1-4946-8718-ca583adc0872" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_ed8ffcd5-6e5d-41d8-bbfb-3aed1b1a3d25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f0b24b17-47c6-4c36-be33-480b7a013751" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_ed8ffcd5-6e5d-41d8-bbfb-3aed1b1a3d25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7fc4d184-6a86-4dbf-852f-fec29e13b7ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f0b24b17-47c6-4c36-be33-480b7a013751" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7fc4d184-6a86-4dbf-852f-fec29e13b7ce" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/BenefitPlansNarrativeDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#BenefitPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/BenefitPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_aeb8231f-bf76-43f7-a577-de46b747fea9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0090e22e-bce7-4b17-af17-9f45221997d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_aeb8231f-bf76-43f7-a577-de46b747fea9" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0090e22e-bce7-4b17-af17-9f45221997d5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_18ca70c9-07d5-43d9-b286-74bc53db7861" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0090e22e-bce7-4b17-af17-9f45221997d5" xlink:to="loc_srt_TitleOfIndividualAxis_18ca70c9-07d5-43d9-b286-74bc53db7861" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_18ca70c9-07d5-43d9-b286-74bc53db7861_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_18ca70c9-07d5-43d9-b286-74bc53db7861" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_18ca70c9-07d5-43d9-b286-74bc53db7861_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_eb293498-9518-4307-ab27-28c543a5bf1b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_18ca70c9-07d5-43d9-b286-74bc53db7861" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_eb293498-9518-4307-ab27-28c543a5bf1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_CTWSEmployeesMember_3ad8a4c2-a703-4cf4-8c26-c3d50b5fe28b" xlink:href="sjw-20250331.xsd#sjw_CTWSEmployeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_eb293498-9518-4307-ab27-28c543a5bf1b" xlink:to="loc_sjw_CTWSEmployeesMember_3ad8a4c2-a703-4cf4-8c26-c3d50b5fe28b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_DefinedBenefitPlanRateOfCompensationIncrease_0f9e3914-edc2-424d-83c5-6c093b088682" xlink:href="sjw-20250331.xsd#sjw_DefinedBenefitPlanRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_aeb8231f-bf76-43f7-a577-de46b747fea9" xlink:to="loc_sjw_DefinedBenefitPlanRateOfCompensationIncrease_0f9e3914-edc2-424d-83c5-6c093b088682" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsCurrentFiscalYear_f7064092-10d3-498b-a685-a1f9a552b34f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_aeb8231f-bf76-43f7-a577-de46b747fea9" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsCurrentFiscalYear_f7064092-10d3-498b-a685-a1f9a552b34f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_2e71a433-c626-4ee2-a0e1-2944a75d94b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_aeb8231f-bf76-43f7-a577-de46b747fea9" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_2e71a433-c626-4ee2-a0e1-2944a75d94b4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/BenefitPlansScheduleofNetBenefitCostsDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#BenefitPlansScheduleofNetBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/BenefitPlansScheduleofNetBenefitCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45650d7e-9224-458e-8f7d-b362eaa2a78a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45650d7e-9224-458e-8f7d-b362eaa2a78a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2bd2a2cc-25d1-4f90-bd82-4d88333c7760" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45650d7e-9224-458e-8f7d-b362eaa2a78a" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2bd2a2cc-25d1-4f90-bd82-4d88333c7760" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2bd2a2cc-25d1-4f90-bd82-4d88333c7760_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2bd2a2cc-25d1-4f90-bd82-4d88333c7760" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2bd2a2cc-25d1-4f90-bd82-4d88333c7760_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_b3057fee-37b5-4926-8352-c076eb04f78d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2bd2a2cc-25d1-4f90-bd82-4d88333c7760" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_b3057fee-37b5-4926-8352-c076eb04f78d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_240b8a30-9502-4685-a171-5f1939513d5b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_b3057fee-37b5-4926-8352-c076eb04f78d" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_240b8a30-9502-4685-a171-5f1939513d5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2102ebe0-e96e-4bc1-98c2-62ca70866753" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_b3057fee-37b5-4926-8352-c076eb04f78d" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_2102ebe0-e96e-4bc1-98c2-62ca70866753" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_a37a9d6d-7215-4708-95a5-962ad6bce5e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_a37a9d6d-7215-4708-95a5-962ad6bce5e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_e06317d0-befc-4498-96dd-1e4775370450" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_e06317d0-befc-4498-96dd-1e4775370450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_56d27902-f25b-4f45-bb5c-b9ed43af4c56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_56d27902-f25b-4f45-bb5c-b9ed43af4c56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_96e73a4d-5b3d-45cb-bcb2-b32ba4bf91f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_96e73a4d-5b3d-45cb-bcb2-b32ba4bf91f4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_b37799b3-7ded-4bad-b3ad-45fb136ad65c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_b37799b3-7ded-4bad-b3ad-45fb136ad65c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_afdc4205-e416-4a07-951d-095d0473522d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c8545ada-cb03-489b-a147-a6058adefc1a" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_afdc4205-e416-4a07-951d-095d0473522d" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/EquityPlansNarrativeDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#EquityPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/EquityPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5b8d06df-848c-4670-a38a-18098f576549" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5b8d06df-848c-4670-a38a-18098f576549" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_4f3447a1-a731-4321-b716-ed88ef4b6b01" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5b8d06df-848c-4670-a38a-18098f576549" xlink:to="loc_us-gaap_AwardTypeAxis_4f3447a1-a731-4321-b716-ed88ef4b6b01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4f3447a1-a731-4321-b716-ed88ef4b6b01_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4f3447a1-a731-4321-b716-ed88ef4b6b01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4f3447a1-a731-4321-b716-ed88ef4b6b01_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7248d918-c453-4dd6-a446-1939bf488c9a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4f3447a1-a731-4321-b716-ed88ef4b6b01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7248d918-c453-4dd6-a446-1939bf488c9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_RestrictedStockAndDeferredRestrictedStockMember_fd4a9907-ff47-49a5-9eed-3523946bbd77" xlink:href="sjw-20250331.xsd#sjw_RestrictedStockAndDeferredRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7248d918-c453-4dd6-a446-1939bf488c9a" xlink:to="loc_sjw_RestrictedStockAndDeferredRestrictedStockMember_fd4a9907-ff47-49a5-9eed-3523946bbd77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_19fc821e-3413-41ea-85ef-7a6c5bfdaaec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7248d918-c453-4dd6-a446-1939bf488c9a" xlink:to="loc_us-gaap_PerformanceSharesMember_19fc821e-3413-41ea-85ef-7a6c5bfdaaec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_MarketbasedRSUMember_e56fa3f2-dac7-4722-b78d-5578fe1e24e1" xlink:href="sjw-20250331.xsd#sjw_MarketbasedRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7248d918-c453-4dd6-a446-1939bf488c9a" xlink:to="loc_sjw_MarketbasedRSUMember_e56fa3f2-dac7-4722-b78d-5578fe1e24e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_7c727229-3313-4ff4-b118-fab13949af5f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5b8d06df-848c-4670-a38a-18098f576549" xlink:to="loc_us-gaap_PlanNameAxis_7c727229-3313-4ff4-b118-fab13949af5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_7c727229-3313-4ff4-b118-fab13949af5f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_7c727229-3313-4ff4-b118-fab13949af5f" xlink:to="loc_us-gaap_PlanNameDomain_7c727229-3313-4ff4-b118-fab13949af5f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_895f7251-44b3-4da8-af2d-117d8f31ba50" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_7c727229-3313-4ff4-b118-fab13949af5f" xlink:to="loc_us-gaap_PlanNameDomain_895f7251-44b3-4da8-af2d-117d8f31ba50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_IncentivePlanMember_1451c627-132d-4949-8b10-f99551bd37a4" xlink:href="sjw-20250331.xsd#sjw_IncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_895f7251-44b3-4da8-af2d-117d8f31ba50" xlink:to="loc_sjw_IncentivePlanMember_1451c627-132d-4949-8b10-f99551bd37a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_EmployeeStockPurchasePlanMember_1ee7116c-c0ae-4631-b53a-5112f69eac47" xlink:href="sjw-20250331.xsd#sjw_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_895f7251-44b3-4da8-af2d-117d8f31ba50" xlink:to="loc_sjw_EmployeeStockPurchasePlanMember_1ee7116c-c0ae-4631-b53a-5112f69eac47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_10382c0a-196b-46f0-97bd-2c91a44b8751" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5b8d06df-848c-4670-a38a-18098f576549" xlink:to="loc_srt_RangeAxis_10382c0a-196b-46f0-97bd-2c91a44b8751" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_10382c0a-196b-46f0-97bd-2c91a44b8751_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_10382c0a-196b-46f0-97bd-2c91a44b8751" xlink:to="loc_srt_RangeMember_10382c0a-196b-46f0-97bd-2c91a44b8751_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e01fa34a-7b22-4d0a-8b09-9ff62c3fbca1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_10382c0a-196b-46f0-97bd-2c91a44b8751" xlink:to="loc_srt_RangeMember_e01fa34a-7b22-4d0a-8b09-9ff62c3fbca1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a0f99006-ca25-4762-a995-adeb41926c8c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e01fa34a-7b22-4d0a-8b09-9ff62c3fbca1" xlink:to="loc_srt_MaximumMember_a0f99006-ca25-4762-a995-adeb41926c8c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_e88cedd7-ef2b-46c5-9807-6adf0c8773ca" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e01fa34a-7b22-4d0a-8b09-9ff62c3fbca1" xlink:to="loc_srt_MinimumMember_e88cedd7-ef2b-46c5-9807-6adf0c8773ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuableUponExercise_b6d1551e-3be6-4758-b47d-ba716a5069d9" xlink:href="sjw-20250331.xsd#sjw_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuableUponExercise"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_sjw_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuableUponExercise_b6d1551e-3be6-4758-b47d-ba716a5069d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_107c7509-d713-4b1e-b02f-3930c894ff19" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_107c7509-d713-4b1e-b02f-3930c894ff19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_bbacd219-9f5f-4b04-bc68-c13618cc6fb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_bbacd219-9f5f-4b04-bc68-c13618cc6fb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_20e9eb9d-a796-4434-9e40-5cd216452bfc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_20e9eb9d-a796-4434-9e40-5cd216452bfc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_39aa3e52-86c8-4c40-bb47-ecc443bdfd21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_39aa3e52-86c8-4c40-bb47-ecc443bdfd21" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_e9c70113-0594-40fe-89a3-77eb9976e99d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_e9c70113-0594-40fe-89a3-77eb9976e99d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_ef25b4eb-09ec-41fd-befd-def9b47699a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_ef25b4eb-09ec-41fd-befd-def9b47699a2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_eeaa8513-255e-4ab8-8d93-b0098f2e59a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_214c0f87-7240-4d98-aea5-3a50e6a1538f" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_eeaa8513-255e-4ab8-8d93-b0098f2e59a4" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/EquityPlansCompensationCostsChargedtoIncomebyAwardTypeandProceedsfromESPPDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#EquityPlansCompensationCostsChargedtoIncomebyAwardTypeandProceedsfromESPPDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/EquityPlansCompensationCostsChargedtoIncomebyAwardTypeandProceedsfromESPPDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ca9f1b94-bbde-4421-b628-e0f178dbb422" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a7c52f-6c91-45bc-bccc-38ea2866f75a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ca9f1b94-bbde-4421-b628-e0f178dbb422" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a7c52f-6c91-45bc-bccc-38ea2866f75a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_25ba7c4e-8632-4e52-95c8-fffb82b55b59" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a7c52f-6c91-45bc-bccc-38ea2866f75a" xlink:to="loc_us-gaap_PlanNameAxis_25ba7c4e-8632-4e52-95c8-fffb82b55b59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_25ba7c4e-8632-4e52-95c8-fffb82b55b59_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_25ba7c4e-8632-4e52-95c8-fffb82b55b59" xlink:to="loc_us-gaap_PlanNameDomain_25ba7c4e-8632-4e52-95c8-fffb82b55b59_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_3505c52d-17db-40a1-9955-8cf5c22d8d66" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_25ba7c4e-8632-4e52-95c8-fffb82b55b59" xlink:to="loc_us-gaap_PlanNameDomain_3505c52d-17db-40a1-9955-8cf5c22d8d66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_EmployeeStockPurchasePlanMember_30130bdb-c0ee-4c78-9701-04f05d16e0d8" xlink:href="sjw-20250331.xsd#sjw_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_3505c52d-17db-40a1-9955-8cf5c22d8d66" xlink:to="loc_sjw_EmployeeStockPurchasePlanMember_30130bdb-c0ee-4c78-9701-04f05d16e0d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_dcb06324-c145-44de-bfa1-fc217eb8b02d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a7c52f-6c91-45bc-bccc-38ea2866f75a" xlink:to="loc_us-gaap_AwardTypeAxis_dcb06324-c145-44de-bfa1-fc217eb8b02d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dcb06324-c145-44de-bfa1-fc217eb8b02d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_dcb06324-c145-44de-bfa1-fc217eb8b02d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dcb06324-c145-44de-bfa1-fc217eb8b02d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ffadb510-822c-402a-a705-5a623f3224d6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_dcb06324-c145-44de-bfa1-fc217eb8b02d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ffadb510-822c-402a-a705-5a623f3224d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_RestrictedStockAndDeferredRestrictedStockMember_d08f16a9-4098-4ee2-94ab-9bf6fd70fffe" xlink:href="sjw-20250331.xsd#sjw_RestrictedStockAndDeferredRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ffadb510-822c-402a-a705-5a623f3224d6" xlink:to="loc_sjw_RestrictedStockAndDeferredRestrictedStockMember_d08f16a9-4098-4ee2-94ab-9bf6fd70fffe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_eb0bd38d-7866-47af-a259-da22d9462610" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ca9f1b94-bbde-4421-b628-e0f178dbb422" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_eb0bd38d-7866-47af-a259-da22d9462610" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_b2e39bef-c38a-4f54-ac47-6c4391e6dc7f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ca9f1b94-bbde-4421-b628-e0f178dbb422" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_b2e39bef-c38a-4f54-ac47-6c4391e6dc7f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.sjwater.com/role/SegmentReportingReportableSegmentandOtherBusinessActivitiesDetails" xlink:type="simple" xlink:href="sjw-20250331.xsd#SegmentReportingReportableSegmentandOtherBusinessActivitiesDetails"/>
  <link:definitionLink xlink:role="http://www.sjwater.com/role/SegmentReportingReportableSegmentandOtherBusinessActivitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_809f6b03-a7b6-479d-b06c-0e2288a23842" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_809f6b03-a7b6-479d-b06c-0e2288a23842" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_b53900bf-fcde-46aa-adff-683d9a5b16e9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_809f6b03-a7b6-479d-b06c-0e2288a23842" xlink:to="loc_srt_ConsolidationItemsAxis_b53900bf-fcde-46aa-adff-683d9a5b16e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_b53900bf-fcde-46aa-adff-683d9a5b16e9_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_b53900bf-fcde-46aa-adff-683d9a5b16e9" xlink:to="loc_srt_ConsolidationItemsDomain_b53900bf-fcde-46aa-adff-683d9a5b16e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_93ad37b2-ec58-4fa2-afcc-837f6ecd84ad" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_b53900bf-fcde-46aa-adff-683d9a5b16e9" xlink:to="loc_srt_ConsolidationItemsDomain_93ad37b2-ec58-4fa2-afcc-837f6ecd84ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_a7cf2399-16e8-4364-8b92-cdde96bbddb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_93ad37b2-ec58-4fa2-afcc-837f6ecd84ad" xlink:to="loc_us-gaap_OperatingSegmentsMember_a7cf2399-16e8-4364-8b92-cdde96bbddb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_0ecd8ef6-b6ba-45d6-84d6-05a74f7ebf2f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_93ad37b2-ec58-4fa2-afcc-837f6ecd84ad" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_0ecd8ef6-b6ba-45d6-84d6-05a74f7ebf2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_74af5354-7cf9-4a38-bb9e-d8eaa88c4ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_93ad37b2-ec58-4fa2-afcc-837f6ecd84ad" xlink:to="loc_us-gaap_CorporateNonSegmentMember_74af5354-7cf9-4a38-bb9e-d8eaa88c4ba8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_809f6b03-a7b6-479d-b06c-0e2288a23842" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46" xlink:to="loc_us-gaap_SegmentDomain_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_64fc259f-35d7-4da3-99bc-61459c4f61c8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_e7d4e9c2-9ec7-4119-9ac1-7470559c5f46" xlink:to="loc_us-gaap_SegmentDomain_64fc259f-35d7-4da3-99bc-61459c4f61c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sjw_WaterUtilityServicesMember_2265e173-4675-4a94-ae2e-f53113d265db" xlink:href="sjw-20250331.xsd#sjw_WaterUtilityServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_64fc259f-35d7-4da3-99bc-61459c4f61c8" xlink:to="loc_sjw_WaterUtilityServicesMember_2265e173-4675-4a94-ae2e-f53113d265db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_2d710f1c-2bc0-4d52-b88d-e2794738ddd5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_Revenues_2d710f1c-2bc0-4d52-b88d-e2794738ddd5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WaterProductionCosts_9c1bcc2f-89b8-41d8-9d95-4deff7481128" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WaterProductionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_WaterProductionCosts_9c1bcc2f-89b8-41d8-9d95-4deff7481128" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_42666b06-40da-431c-9cac-f5a5ecf7fbc0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_42666b06-40da-431c-9cac-f5a5ecf7fbc0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilitiesOperatingExpenseMaintenance_6a3df496-3fa8-44ac-b26f-0b9b0cf5105a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UtilitiesOperatingExpenseMaintenance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_UtilitiesOperatingExpenseMaintenance_6a3df496-3fa8-44ac-b26f-0b9b0cf5105a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilitiesOperatingExpenseTaxes_8565bf62-ca53-4140-b8fa-c792dac446b6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UtilitiesOperatingExpenseTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_UtilitiesOperatingExpenseTaxes_8565bf62-ca53-4140-b8fa-c792dac446b6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization_4c30c1a3-a20c-468a-b7bb-3dee85d3f907" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization_4c30c1a3-a20c-468a-b7bb-3dee85d3f907" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_f27609a1-088a-4406-b833-25deeb9dbe02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_InterestExpenseDebt_f27609a1-088a-4406-b833-25deeb9dbe02" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_9f48b372-fc23-4c74-b93e-f4120ca566da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_9f48b372-fc23-4c74-b93e-f4120ca566da" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_8af3b3af-91d7-49a2-b05b-facd5d51ef83" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_b13bbcfc-a947-4414-a599-d1d381ac4d44" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_8af3b3af-91d7-49a2-b05b-facd5d51ef83" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_1cfd8600-ce95-4844-9e6e-cff23184166c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_NetIncomeLoss_1cfd8600-ce95-4844-9e6e-cff23184166c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_c9f3f784-09c1-45f4-91d4-83576d7c169c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_c9f3f784-09c1-45f4-91d4-83576d7c169c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_4d1e5569-847c-42f2-89e7-d7b9859d2a55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_e0f3155e-5d03-4ebf-b537-85a8c76ae411" xlink:to="loc_us-gaap_Assets_4d1e5569-847c-42f2-89e7-d7b9859d2a55" xlink:type="arc" order="4"/>
  </link:definitionLink>
</link:linkbase>
