UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of June 2026

Commission File Number: 001-39974

LOGO

WEST FRASER TIMBER CO. LTD.

(Exact name of Registrant, as specified in its charter)

1500 - 885 West Georgia Street

Vancouver, British Columbia

Canada, V6C 3E8

Tel: (604) 895-2700

(Address and Telephone Number of Registrant’s Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☐ Form 40-F ☒

EXHIBIT INDEX


Exhibit		Description

99.1		News release dated June 3, 2026 re: West Fraser Releases 2025 Sustainability Report.

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, thereunto duly authorized.

Date: June 3, 2026

WEST FRASER TIMBER CO. LTD.

/S/ Chistopher A. Virostek

Christopher A. Virostek

Executive Vice-President and Chief Financial Officer

WEST FRASER TIMBER CO., LTD 6-K