Executive Change

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549       FORM 8-K       CURRENT REPORT   PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934   Date of Report (Date of earliest event reported): September 29, 2023     Westamerica Bancorporation (Exact name of registrant as specified in its charter)                 California   001-09383   94-2156203 (State or other jurisdiction of incorporation)   (Commission File No.)   (IRS Employer Identification Number)     1108 Fifth Avenue San Rafael , California   94901 (Address of principal executive offices)   (Zip Code)   Registrant’s telephone number, including area code:  (707) 863-6000       Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):   ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)   ☐ Soliciting material pursuant to rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)   ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))   ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))   Securities registered pursuant to Section 12(b) of the Exchange Act:   Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, no par value WABC The Nasdaq Stock Market, LLC   Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2). Emerging growth company ¨   If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the exchange Act. ¨       Section 5 – Corporate Governance and Management   Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers   Election of Director   On September 28, 2023, the Westamerica Bancorporation Board of Directors appointed Alisa Belew to serve as an independent member of the Board of Directors effective October 26, 2023 until her successor is duly nominated, qualified, and elected.   Ms. Belew serves as Director of Newmark, were she specializes in the leasing and sales of commercial properties in Marin and Sonoma counties.         2     SIGNATURES   Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.                         WESTAMERICA BANCORPORATION                    (Registrant)         Date: September 29, 2023       By:   /s/ John “Robert” Thorson             John “Robert” Thorson             Senior Vice President and Chief Financial Officer                   3