6-K

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 April 2026

Commission File Number: 000-55607

| (Translation of registrant’s name into English) |

Suite 2070, 1188 West Georgia Street, Vancouver, B.C., V6E 4A2

(Address of principal executive office)

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 ☒

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): ☐

DOCUMENTS INCORPORATED BY REFERENCE

Exhibits 99.1 and 99.2 to this Report on Form 6-K are hereby incorporated by reference as Exhibits to the Registration Statement on Form F-10 of First Mining Gold Corp. (File No. 333-231801).

DOCUMENTS FILED AS PART OF THIS FORM 6-K

| 99.1 | Notice of Meeting and Record Date |

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.

| | (Registrant) | | Date: April 7, 2026 | /s/ Richard Huang |

| | Richard Huang |

| | VP, Corporate Development & Corporate Secretary |

EXHIBIT INDEX

| 99.1 | Notice of Meeting and Record Date |

firstmining_ex991.htm EXHIBIT 99.1

To: All Canadian Securities Regulatory Authorities

Subject: FIRST MINING GOLD CORP.

Dear Sir/Madam:

We advise of the following with respect to the upcoming Meeting of Security Holders for the subject Issuer:

| Record Date for Notice of Meeting : | April 21, 2026 |

| Record Date for Voting (if applicable) : | April 21, 2026 |

| Beneficial Ownership Determination Date : | April 21, 2026 |

| Meeting Date : | June 09, 2026 |

| Meeting Location (if available) : | No |

| Issuer sending proxy related materials directly to NOBO: | Vancouver, BC |

| Issuer paying for delivery to OBO: | Yes | | Notice and Access (NAA) Requirements: | |

| NAA for Beneficial Holders | Yes |

| Beneficial Holders Stratification Criteria: | Not Applicable |

| NAA for Registered Holders | Yes |

| Registered Holders Stratification Criteria: | Not Applicable |

Voting Security Details:

| COMMON SHARES | 320890106 | CA3208901064 |

Sincerely,

Computershare

Agent for FIRST MINING GOLD CORP.