EX-32.0

Certification pursuant to 18 U.S.C. Section 1350,

as adopted pursuant to Section 906

of the Sarbanes-Oxley Act of 2002

Thomas J. Kemly, President and Chief Executive Officer, and Dennis E. Gibney, Executive Vice President and Chief Financial Officer of Columbia Financial Inc. (the “Company”), each certify in his capacity as an officer of the Company that he has reviewed the annual report of the Company on Form 10-K for the year ended December 31, 2023 and that to the best of his knowledge:

(1) the report fully complies with the requirements of Sections 13(a) 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 Company.

Date:	February 29, 2024	/s/Thomas J. Kemly
		Thomas J. Kemly
		President and Chief Executive Officer
Date:	February 29, 2024	/s/Dennis E. Gibney
		Dennis E. Gibney
		Executive Vice President and Chief Financial Officer

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.