SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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 March 2023

Commission File Number: 333-225606

ALTAGAS LTD.

(Translation of Registrant’s Name into English)

1700, 355 – 4th Avenue S.W., Calgary, Alberta, T2P 0J1, Canada

(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 x

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 1.1 to this report on Form 6-K is hereby incorporated by reference into the registrant’s Registration Statement on Form F-10 (333-253122). The remaining exhibit to this report on Form 6-K are furnished, not filed, and will not be incorporated by reference into any registration statement filed by the registrant under the Securities Act of 1933, as amended.

EXHIBIT INDEX

1.1 Earnings coverage ratio.

99.1 A copy of the registrant's News Release dated March 2 , 20 23.

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.

ALTAGAS LTD.

Date: March 2, 2023

By: /s/ Brad Grant

Name: Brad Grant

Title: Executive Vice President, Chief Legal Officer

AltaGas Ltd. 6-K