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 February 2023

Commission File Number 001-40924

ALGOMA STEEL GROUP INC.

(Exact name of Registrant as specified in its charter)

N/A

(Translation of Registrant’s name into English)

105 West Street Sault Ste. Marie, Ontario

P6A 7B4, Canada (705) 945-2351

(Address of principal executive offices)

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  ☐

EXHIBIT INDEX

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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.

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EX-99.1

Exhibit 99.1

MEDIA RELEASE

February 1, 2023

Algoma Steel toAnnounce Fiscal 2023 Third Quarter Results February 13, 2023

SAULT STE. MARIE, Ontario, February 1, 2023—Algoma Steel Group Inc. (NASDAQ: ASTL; TSX: ASTL) (“Algoma”), a leading Canadian producer of hot and cold rolled steel sheet and plate products, announced today that the Company will release its fiscal 2023 third quarter financial results after the market closes on Monday, February 13, 2023. A webcast and conference call will be held on Tuesday, February 14, 2023, at 11:00 a.m. Eastern Time to review the Company’s results, discuss recent events, and conduct a question-and-answer session.

The live webcast and archived replay of the conference call can be accessed on the Investors section of the Company’s website at www.algoma.com. For those unable to access the webcast, the conference call will be accessible domestically or internationally by dialing 877-425-9470 or 201-389-0878, respectively. Upon dialing in, please request to join the Algoma Steel Fiscal Third Quarter Conference Call. To access the replay of the call, dial 844-512-2921 (domestic) or 412-317-6671 (international) with passcode 13735595.

CautionaryStatement Regarding Forward-Looking Statements

This news release contains “forward-looking information” under applicable Canadian securities legislation and “forward-looking statements” within the meaning of the U.S. Private Securities Litigation Reform Act of 1995 (collectively, “forward-looking statements”), including statements regarding Algoma’s transition to electric arc steelmaking, its future as a leading producer of green steel, and Algoma’s modernization of its plate mill facilities, transformation journey, ability to deliver greater value, ability to offer North America a secure steel supply and a sustainable future, and investment in its people, and processes. These forward-looking statements generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “plan,” “pipeline,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are predictions, projections, and other statements about future events that are based on current expectations and assumptions. Many factors could cause actual future events to differ materially from the forward-looking statements in this document. Readers should consider the risks and uncertainties set forth in the section entitled “Risk Factors” and “Cautionary Note Regarding Forward-Looking Statements” in Algoma’s Annual

Algoma Steel Inc. | 105 West Street, Sault Ste. Marie, ON, Canada P6A 7B4 | T: 705-945-2351 F: 705-945-2203 | algoma.com

YOUR PARTNER IN STEEL. SINCE 1901

Report on Form 20-F, filed by Algoma with the Ontario Securities Commission (the “OSC”) (available under the company’s SEDAR profile at www.sedar.com) and with the Securities and Exchange Commission (the “SEC”) (available at www.sec.gov), as well as in Algoma’s current reports with the OSC and SEC. Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements, and Algoma assumes no obligation and does not intend to update or revise these forward-looking statements, whether as a result of new information, future events, or otherwise.

About Algoma Steel Group Inc.

Based in Sault Ste. Marie, Ontario, Canada, Algoma is a fully integrated producer of hot and cold rolled steel products including sheet and plate. Driven by a purpose to build better lives and a greener future, Algoma is positioned to deliver responsive, customer-driven product solutions to applications in the automotive, construction, energy, defense, and manufacturing sectors. Algoma is a key supplier of steel products to customers in North America and is the only producer of discrete plate products in Canada. Its state-of-the-art Direct Strip Production Complex (“DSPC”) is one of the lowest-cost producers of hot rolled sheet steel (HRC) in North America.

Algoma is on a transformation journey, modernizing its plate mill and adopting electric arc technology that builds on the strong principles of recycling and environmental stewardship to significantly lower carbon emissions. Today Algoma is investing in its people and processes, working safely, as a team to become one of North America’s leading producers of green steel.

As a founding industry in their community, Algoma is drawing on the best of its rich steelmaking tradition to deliver greater value, offering North America the comfort of a secure steel supply and a sustainable future as your partner in steel.

For more information, please contact:

Mike Moraca

Treasurer and Investor Relations Officer

Algoma Steel Inc.

Phone: 705.945.3300

E-mail: IR@algoma.com

Algoma Steel Inc. | 105 West Street, Sault Ste. Marie, ON, Canada P6A 7B4 | T: 705-945-2351 F: 705-945-2203 | algoma.com

YOUR PARTNER IN STEEL. SINCE 1901

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