UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) OR (g) OF

THE SECURITIES EXCHANGE ACT OF 1934

Catalyst Bancorp, Inc.

(Exact name of registrant as specified in its charter)

Securities to be registered pursuant to Section 12(b) of the Act:

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c) or (e), check the following box.  x

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d) or (e), check the following box.  ¨

If this form relates to the registration of a class of securities concurrently with a Regulation A offering, check the following box.  ¨

Securities Act registration statement file number to which this form relates: 333-254200

Securities to be registered pursuant to Section 12(g) of the Act:

None

The description of the common stock, $0.01 par value per share, of Catalyst Bancorp, Inc. (the “Registrant”), is incorporated by reference to the “Description of Capital Stock,” “Our Dividend Policy” and “Market for the Common Stock” in the prospectus that constitutes a part of the Registration Statement on Form S-1 (File No. 333-254200) initially filed by the Registrant with the Securities and Exchange Commission on March 12, 2021, as subsequently amended from time to time thereafter (the “Registration Statement”). The description of the common stock included in any form of prospectus subsequently filed by the Registrant pursuant to Section 424(b) of the Securities Act of 1933, as amended, shall also be deemed to be incorporated herein by reference.

For a description of the provisions of the Registrant’s Articles of Incorporation and Bylaws that may render a change in control of the Registrant more difficult, reference is made to “Restrictions on Acquisition of Catalyst Bancorp” and “Description of Capital Stock” in the Registration Statement.

In accordance with the “Instructions as to Exhibits” to Form 8-A, no exhibits are required to be filed as part of this registration statement because no other securities of the Registrant are registered on The Nasdaq Stock Market LLC and the securities registered hereby are not being registered pursuant to Section 12(g) of the Securities Exchange Act of 1934, as amended.

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized.