Exhibit 32

CERTIFICATION OF 

CHIEF EXECUTIVE OFFICER, PRINCIPAL FINANCIAL OFFICER AND PRINCIPAL ACCOUNTING OFFICER UNDER SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 

This certification is given by the undersigned Chief Executive Officer, Principal Financial Officer and Principal Accounting Officer of Columbia Banking System, Inc. (the “registrant”) pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. Each of the undersigned hereby certifies, with respect to the registrant's annual report on Form 10-K for the period ended December 31, 2023 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the registrant

/s/ Clint E. Stein

Clint E. Stein

President and Chief Executive Officer

Columbia Banking System, Inc.

/s/ Ronald L. Farnsworth

Ronald L. Farnsworth

Chief Financial Officer and Principal Financial Officer

Columbia Banking System, Inc.

/s/ Lisa M. White

Lisa M. White

Corporate Controller and Principal Accounting Officer

Columbia Banking System, Inc.

February 27, 2024