Company: WFG
Filing Date: 2025-07-23
Form Type: 6-K
Source: 0001402388-25-000012
Chunk: 0

Company: WEST FRASER TIMBER CO., LTD
Filing Date: 2025-07-23
Form: 6-K
Chunk 0
---
### 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 July 2025

#### Commission File Number: 001-39974

#### WEST FRASER TIMBER CO. LTD.
<div align='center'>(Exact name of Registrant, as specified in its charter)</div>

#### 1500 - 885 West Georgia Street

#### Vancouver, British Columbia

#### Canada, V6C 3E8

#### Tel: (604) 895-2700
<div align='center'>(Address and Telephone Number of Registrant's Principal Executive Offices)</div>

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

<div align='center'>Form 20-F ☐ Form 40-F ☒</div>

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

### EXHIBIT INDEX

### 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: July 23, 2025                                        |
|:-----------------------------------------------------------|
| WEST FRASER TIMBER CO. LTD.                                |
| /s/ Christopher A. Virostek                                |
| Christopher A. Virostek                                    
 Senior Vice-President, Finance and Chief Financial Officer |