TIMBERLAND BANCORP INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of theSecurities Exchange Act of 1934 (Amendment No. __)

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☐ Preliminary Proxy Statement

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■ Definitive Proxy Statement

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TIMBERLAND BANCORP, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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Dear Shareholder:

You are cordially invited to attend the annual meeting of shareholders of Timberland Bancorp, Inc. The meeting will be held on Tuesday, January 27, 2026 at 1:00 p.m., local time. Our 2026 annual meeting of shareholders will be a virtual meeting conducted solely online and can be attended by visiting www.virtualshareholdermeeting.com/TSBK2026. To participate in the annual meeting, you will need the control number located on your proxy card or on the instructions that accompanied your proxy materials. You will not be able to attend the annual meeting in person.

The Notice of Annual Meeting of Shareholders and Proxy Statement appearing on the following pages describe the formal business to be transacted at the meeting. During the meeting, we will also report on our operations. Directors and officers of Timberland Bancorp, Inc., as well as a representative of Delap LLP, our independent registered public accounting firm for the fiscal year ended September 30, 2025, will be present to respond to appropriate questions of shareholders.

It is important that your shares are represented at the meeting, whether or not you attend the virtual meeting and regardless of the number of shares you own. To make sure your shares are represented, we urge you to vote promptly. You may vote your shares via the Internet or a toll-free telephone number, or by completing and mailing the enclosed proxy card. If you attend the virtual meeting, you may vote even if you have previously submitted your proxy.

We look forward to seeing you at the meeting.

Sincerely,

/s/Michael J. Stoney

Michael J. Stoney

Board Chair