6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANTTO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of December 2025

Commission File Number: 000-55607

First MiningGold Corp.

(Translation of registrant's name into English)

Suite 2070, 1188 West Georgia Street, Vancouver, B.C., V6E4A2

(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 ☒

DOCUMENTS FILED AS PART OF THIS FORM 6-K

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.

Exhibit 99.1

First Mining Announces Receipt of $6 Million in Proceeds from Warrants Exercise

VANCOUVER, BC, Dec. 16, 2025 /CNW/ - First MiningGold Corp. ("First Mining" or the "Company") (TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) is pleased to announce that it has received total proceeds of C$6,410,045 from the exercise by First Majestic Silver Corp. ("First Majestic") of 32,050,228 common share purchase warrants of the Company (the "Warrants") at a price of $0.20 per Warrant.  The Warrants were issued in relation to amending the terms of a silver purchase agreement among First Majestic, First Mining and Gold Canyon Resources Inc., a wholly-owned subsidiary of First Mining.

The Company intends to use the proceeds from the exercise of these Warrants to advance First Mining's Springpole and Duparquet gold projects, as well as for general working capital and corporate purposes.

Following the exercise of the Warrants, First Majestic's ownership in First Mining increases to 47,379,944 common shares representing 3.5% of the total common shares of the Company outstanding.

About First Mining Gold Corp.

First Mining is a gold developer advancing two of the largest gold projects in Canada, the Springpole Gold Project in northwestern Ontario, where we have commenced a Feasibility Study and permitting activities are on-going with a final Environmental Impact Statement / Environmental Assessment for the project submitted in November 2024, and the Duparquet Gold Project in Quebec, a PEA-stage development project located on the Destor-Porcupine Fault Zone in the prolific Abitibi region. First Mining also owns the Cameron Gold Project in Ontario and a 30% project interest in the Pickle Crow Gold Project.

First Mining was established in 2015 by Mr. Keith Neumeyer, founding President and CEO of First Majestic Silver Corp.

ON BEHALF OF FIRST MINING GOLD CORP.

Daniel W. Wilton

Chief Executive Officer and Director

Cautionary Note Regarding Forward-Looking Statements

This news release includes certain "forward-lookinginformation" and "forward-looking statements" (collectively "forward-looking statements") within the meaningof applicable Canadian and United States securities legislation including the United States Private Securities Litigation Reform Act of1995. These forward-looking statements are made as of the date of this news release. Forward-looking statements are frequently, but notalways, identified by words such as "expects", "anticipates", "believes", "plans", "projects","intends", "estimates", "envisages", "potential", "possible", "strategy","goals", "opportunities", "objectives", or variations thereof or stating that certain actions, events orresults "may", "could", "would", "might" or "will" be taken, occur or be achieved, orthe negative of any of these terms and similar expressions.

Forward-looking statements in this news releaserelate to future events or future performance and reflect current estimates, predictions, expectations or beliefs regarding future eventsand include, but are not limited to, the use of proceeds for the Warrants exercise, and First Mining's plans related to its Springpole,Duparquet and other projects.  All forward-looking statements are based on First Mining's or its consultants' current beliefs aswell as various assumptions made by them and information currently available to them. There can be no assurance that such statements willprove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Forward-lookingstatements reflect the beliefs, opinions and projections on the date the statements are made and are based upon a number of assumptionsand estimates that, while considered reasonable by the respective parties, are inherently subject to significant business, economic, competitive,political and social uncertainties and contingencies. Such factors include, without limitation the Company's business, operations andfinancial condition potentially being materially adversely affected by the outbreak of epidemics, pandemics or other health crises, andby reactions by government and private actors to such outbreaks; risks to employee health and safety as a result of the outbreak of epidemics,pandemics or other health crises, that may result in a slowdown or temporary suspension of operations at some or all of the Company'smineral properties as well as its head office; fluctuations in the spot and forward price of gold, silver, base metals or certainother commodities; fluctuations in the currency markets (such as the Canadian dollar versus the U.S. dollar); changes in national andlocal government, legislation, taxation, controls, regulations and political or economic developments; risks and hazards associated withthe business of mineral exploration, development and mining (including environmental hazards, industrial accidents, unusual or unexpectedformations, pressures, cave-ins and flooding); the presence of laws and regulations that may impose restrictions on mining; employee relations;relationships with and claims by local communities, indigenous populations and other stakeholders; availability and increasing costs associatedwith mining inputs and labour; the speculative nature of mineral exploration and development; title to properties.; and the additionalrisks described in the Company's Annual Information Form for the year ended December 31, 2024 filed with the Canadian securities regulatoryauthorities under the Company's SEDAR+ profile at www.sedarplus.ca, and in the Company's Annual Report on Form 40-F filed with the SECon EDGAR.

First Mining cautions that the foregoing list offactors that may affect future results is not exhaustive. When relying on our forward-looking statements to make decisions with respectto First Mining, investors and others should carefully consider the foregoing factors and other uncertainties and potential events. FirstMining does not undertake to update any forward-looking statement, whether written or oral, that may be made from time to time by theCompany or on our behalf, except as required by law.

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SOURCE First Mining Gold Corp.

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%CIK: 0001641229

For further information: For further information, please contact: Toll Free: 1 844 306 8827 | Email: info@firstmininggold.com; Paul Morris | Director, Investor Relations | Email: paul@firstmininggold.com

CO: First Mining Gold Corp.

CNW 07:00e 16-DEC-25