Company: SAND
Filing Date: 2025-09-15
Form Type: 6-K
Source: 0001193125-25-202859
Chunk: 0

Company: SANDSTORM GOLD LTD
Filing Date: 2025-09-15
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-16OR 15D-16

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of September, 2025

Commission File Number: 001-35617

Sandstorm Gold Ltd.

(Translation of registrant’s name into English)

Suite 3200 - 733 Seymour Street

Vancouver, British Columbia

V6B 0S6 Canada

(Address of principal executive offices)

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

Form 20-F ☐ Form 40-F ☒

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

| Exhibit |     | Description of Exhibit                                        |
| 99.1    |     | Management Information Circular and Notice of Special Meeting |
| 99.2    |     | Form of Proxy                                                 |
| 99.3    |     | Letter of Transmittal                                         |
| 99.4    |     | Voting Instruction Form                                       |
| 99.5    |     | Abridgement Certificate                                       |

SIGNATURE 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: September 15, 2025 |     | SANDSTORM GOLD LTD. 
 By:                 |     | /s/ Erfan Kazemi               |
|:-------------------------|:----|:--------------------|:----|:-------------------------------|
|                          |     |                     |     | Name: Erfan Kazemi             |
|                          |     |                     |     | Title: Chief Financial Officer |