Westamerica Bancorporation adopts amended bylaws and reports shareholder votes at 2023 annual meeting

On April 27, 2023, in connection with the effectiveness of new Securities and Exchange Commission rules regarding universal proxy cards, certain recent changes to the California General Corporation Law (the “CGCL”), and a periodic review of the bylaws of Westamerica Bancorporation (the “Company”), the Company’s board of directors (the “Board”) approved and adopted the Company’s amended and restated bylaws (the “Amended and Restated Bylaws”), which became immediately effective.

Proposal 1. Election of Directors The shareholders elected all of the Board of Directors nominees for a term of one year, as follows: Nominee For Against Abstain Non-Votes Uncast E. Joseph Bowler 18,920,359 1,641,969 42,322 2,135,375 -0- Melanie Chiesa 20,322,831 238,640 43,179 2,135,375 -0- Michele Hassid 19,859,907 698,732 46,011 2,135,375 -0- Catherine C. MacMillan 18,825,343 1,736,043 43,264 2,135,375 -0- Ronald A. Nelson 18,642,461 1,922,227 39,962 2,135,375 -0- David L. Payne 19,958,579 602,788 43,283 2,135,375 -0- Edward B. Sylvester 17,297,900 3,264,214 42,536 2,135,375 -0- Inez Wondeh 20,182,399 376,212 45,957 2,135,375 82

Proposal 3. Approve a Non-Binding Advisory Vote on Frequency of the Advisory Vote on Executive Compensation The shareholders approved, on an advisory non-binding basis, the frequency of advisory votes on named executive officer compensation by the vote. Based on the results of the vote and consistent with the recommendations of the Board of Directors, the Board of Directors has determined to hold an advisory vote on executive compensation every year until the next required advisory vote on the frequency of future advisory votes on executive compensation. 1 Year 2 Years 3 Years Abstain Non-Votes 18,314,074 16,260 2,210,801 63,515 2,135,375

Proposal 2. Approve a Non-Binding Advisory Vote on Executive Compensation The shareholders approved, on an advisory non-binding basis, the compensation of Westamerica Bancorporation’s named executive officers, by the following vote: For Against Abstain Non-Votes 20,037,040 407,524 160,086 2,135,375

Proposal 4. Ratify Selection of Crowe LLP as Company’s Independent Auditors for Fiscal Year 2023 The shareholders ratified the appointment of Crowe LLP as the Company’s independent registered public accounting firm for the year ending December 31, 2023, by the following vote: For Against Abstain Non-Votes 22,538,086 72,862 129,077 -0-