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 2023

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 Files Preliminary Base Shelf Prospectus and Registration Statement

VANCOUVER, BC, Dec. 21, 2023 /CNW/ - FirstMining Gold Corp. ("First Mining" or the "Company") (TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) announces that it has filed a preliminary short form base shelf prospectus (the "Preliminary Shelf Prospectus") with the securities regulatory authorities in each of the provinces of Canada (the "Commissions"), and a corresponding registration statement on Form F-10 (the "Registration Statement") with the United States Securities and Exchange Commission (the "SEC") under the U.S./Canada Multijurisdictional Disclosure System.

First Mining has filed the Preliminary Shelf Prospectus and the Registration Statement to provide the Company with greater financial flexibility going forward but has not entered into any agreements or arrangements to authorize or offer any Securities (as defined below) at this time.

The Preliminary Shelf Prospectus and the Registration Statement remain subject to completion or amendment. Once a receipt for a final short form base shelf prospectus (the "Final Shelf Prospectus") is received from the Commissions and the corresponding Registration Statement is deemed effective by the SEC, First Mining may undertake offerings of common shares (including common shares issued on a "flow-through" basis), preferred shares, warrants, subscription receipts and units (collectively, the "Securities"), or any combination thereof, up to an aggregate total of C$100 million from time to time during the 25-month period that such Final Shelf Prospectus remains effective. The Securities may be offered in amounts, at prices and on terms to be determined at the time of sale and, subject to applicable regulations, may include "at-the-market" transactions, public offerings or strategic investments. The specific terms of any offering of Securities, including the use of proceeds from any offering, will be set forth in one or more shelf prospectus supplement(s) to be filed with applicable securities regulators.

Copies of the Preliminary Shelf Prospectus and the Registration Statement can be found, respectively, under the Company's SEDAR+ profile at www.sedarplus.ca and on EDGAR at www.sec.gov, or may be obtained by request to Richard Huang, Vice President, Corporate Development, Suite 2070 – 1188 West Georgia Street, Vancouver, British Columbia  V6E 4A2, Canada (tel: 1-844-306-8827), or to info@firstmininggold.com.

No securities regulatory authority has eitherapproved or disapproved the contents of this news release. The Registration Statement filed today with the SEC has not yet become effective.No Securities may be sold, nor may offers to buy be accepted, until a receipt for a Final Shelf Prospectus has been issued by the Commissionsand the Registration Statement becomes effective. This news release does not constitute an offer to sell or a solicitation of an offerto buy any securities of the Company in any jurisdiction in which such offer, solicitation or sale would be unlawful.

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 draft Environmental Impact Statement ("EIS") for the project published in June 2022, and the Duparquet 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 portfolio of gold project interests including the Pickle Crow Gold Project (being advanced in partnership with FireFly Metals Ltd), the Hope Brook Gold Project (being advanced in partnership with Big Ridge Gold Corp.), and a large equity interest in Treasury Metals Inc.

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", "targeted", "advancing", "proving"or variations thereof or stating that certain actions, events or results "may", "could", "would", "might"or "will" be taken, occur or be achieved, or the 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, statements with respect to: (i) the filing of and receipt of the Final Shelf Prospectus and the effectivenessof the corresponding Registration Statement; (ii) the filing and effectiveness of any potential prospectus supplement; (iii) the Companyundertaking any offering of Securities under the Final Shelf Prospectus and corresponding Registration Statement, including the amountand terms of any Securities to be offered; (iv) the Company's plans with respect to advancing its portfolio of gold projects; (v) feasibilityand permitting activities related to the Springpole Gold Project; and (vi) realizing the value of the Company's gold projects for theCompany's shareholders. All forward-looking statements are based on First Mining's or its consultants' current beliefs as well as variousassumptions made by them and information currently available to them. There can be no assurance that such statements will prove to beaccurate, and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statementsreflect the beliefs, opinions and projections on the date the statements are made and are based upon a number of assumptions and estimatesthat, while considered reasonable by the respective parties, are inherently subject to significant business, economic, competitive, politicaland social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievementsto be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-lookingstatements and the parties have made assumptions and estimates based on or related to many of these factors.  Such factors include,without limitation: the timing and filing of a Final Shelf Prospectus and corresponding Registration Statement; the potential offeringof any Securities by the Company; uncertainty with respect to the completion of any future offering; the ability to obtain applicableregulatory approval for any contemplated offerings; the ability of the Company to negotiate and complete future funding transactions;fluctuations in the spot and forward price of gold, silver, base metals or certain other commodities; fluctuations in the currency markets(such as the Canadian dollar versus the U.S. dollar); changes in national and local government, legislation, taxation, controls, regulationsand political or economic developments; risks and hazards associated with the business of mineral exploration, development and mining(including environmental hazards, industrial accidents, unusual or unexpected formations, pressures, cave-ins and flooding); the presenceof 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 associated with mining inputs and labour; the speculativenature of mineral exploration and development; title to properties.; and the additional risks described in the Company's Annual InformationForm for the year ended December 31, 2022 filed with the Canadian securities regulatory authorities under the Company's SEDAR+ profileat www.sedarplus.ca, and in the Company's Annual Report on Form 40-F filed with the SEC and on 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: 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 17:16e 21-DEC-23