<?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>2243</noOfUnitsSold>
      <aggregateMarketValue>108949.00</aggregateMarketValue>
      <noOfUnitsOutstanding>26708425</noOfUnitsOutstanding>
      <approxSaleDate>04/28/2025</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>04/04/2019</acquiredDate>
      <natureOfAcquisitionTransaction>Performance Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>WESTAMERICA BANCORPORATION</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1249</amountOfSecuritiesAcquired>
      <paymentDate>04/04/2019</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>03/04/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Performance Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>WESTAMERICA BANCORPORATION</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>994</amountOfSecuritiesAcquired>
      <paymentDate>03/04/2021</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <remarks>Shares sold in this filing were sold in the John A Thorson &amp; Jeanette M Perry-Thorson Revocable Trust.</remarks>
    <noticeSignature>
      <noticeDate>04/28/2025</noticeDate>
      <signature>JOHN A THORSON TTEE</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 3449}]
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
2243
108949.00
26708425
04/28/2025
NASDAQ
Common
04/04/2019
Performance Stock Lapse
WESTAMERICA BANCORPORATION
N
1249
04/04/2019
Equity Compensation
Common
03/04/2021
Performance Stock Lapse
WESTAMERICA BANCORPORATION
N
994
03/04/2021
Equity Compensation
Y
Shares sold in this filing were sold in the John A Thorson & Jeanette M Perry-Thorson Revocable Trust.
04/28/2025
JOHN A THORSON TTEE