<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001201516</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000311094</issuerCik>
      <issuerName>WESTAMERICA BANCORPORATION</issuerName>
      <secFileNumber>001-09383</secFileNumber>
      <issuerAddress>
        <com:street1>1108 FIFTH AVE</com:street1>
        <com:city>SAN RAFAEL</com:city>
        <com:stateOrCountry>CA</com:stateOrCountry>
        <com:zipCode>94901</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>(707) 863-6000</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>THORSON JOHN A</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Former Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Charles Schwab &amp; Co., Inc.</name>
        <address>
          <com:street1>3000 Schwab Way</com:street1>
          <com:city>Westlake</com:city>
          <com:stateOrCountry>TX</com:stateOrCountry>
          <com:zipCode>76262</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>7567</noOfUnitsSold>
      <aggregateMarketValue>391214.00</aggregateMarketValue>
      <noOfUnitsOutstanding>26180675</noOfUnitsOutstanding>
      <approxSaleDate>07/03/2025</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>07/03/2025</acquiredDate>
      <natureOfAcquisitionTransaction>Employee Stock Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>WESTAMERICA BANCORPORATION</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>7567</amountOfSecuritiesAcquired>
      <paymentDate>07/03/2025</paymentDate>
      <natureOfPayment>Broker Payment for Cashless Exercise</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>JOHN A THORSON</name>
        <address>
          <com:street1>1108 FIFTH AVE</com:street1>
          <com:city>SAN RAFAEL</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94901</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>WESTAMERICA BANCORPORATION</securitiesClassTitle>
      <saleDate>04/28/2025</saleDate>
      <amountOfSecuritiesSold>2243</amountOfSecuritiesSold>
      <grossProceeds>108949.00</grossProceeds>
    </securitiesSoldInPast3Months>
    <remarks>Options on this filing may be sold over various dates.</remarks>
    <noticeSignature>
      <noticeDate>07/03/2025</noticeDate>
      <signature>JOHN A THORSON</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
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144
0001201516
XXXXXXXX
LIVE
0000311094
WESTAMERICA BANCORPORATION
001-09383
1108 FIFTH AVE
SAN RAFAEL
CA
94901
(707) 863-6000
THORSON JOHN A
Former Officer
Common
Charles Schwab & Co., Inc.
3000 Schwab Way
Westlake
TX
76262
7567
391214.00
26180675
07/03/2025
NASDAQ
Common
07/03/2025
Employee Stock Option Exercise
WESTAMERICA BANCORPORATION
N
7567
07/03/2025
Broker Payment for Cashless Exercise
N
JOHN A THORSON
1108 FIFTH AVE
SAN RAFAEL
CA
94901
WESTAMERICA BANCORPORATION
04/28/2025
2243
108949.00
Options on this filing may be sold over various dates.
07/03/2025
JOHN A THORSON