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

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of April 2023

Commission File Number: 001-39240

GFL Environmental Inc.

(Translation of registrant’s name intoEnglish)

100 New Park Place, Suite 500

Vaughan, Ontario, Canada L4K 0H9

(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 INDEX

The following exhibit is furnished as part of this Current Report on Form 6-K.

1

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.

2

Exhibit 99.1

GFL Environmental Inc. Appoints Sandra Levy to its Board of Directors

VAUGHAN, ON, April 11, 2023 – GFL Environmental Inc. (NYSE: GFL) (TSX: GFL) ("GFL") today announced that Sandra Levy has been appointed to its Board of Directors, effective April 28, 2023. Ms. Levy’s election will expand the board to 10 directors, nine of whom are independent.

Ms. Levy is a two-time Canadian Olympic athlete in the sport of field hockey and is a senior human resources executive with over 25 years of experience in human resources and legal roles. She is the current Chief People & Culture Officer at the Canadian Olympic Committee, a position she has held since 2020. Prior to joining the Canadian Olympic Committee, Ms. Levy served as Vice-President, Human Resources of RioCan Management Inc. from 2018 to 2020 and as Vice President, People and Corporate Affairs of First Capital Asset Management ULC from 2015 to 2018. She currently is a member of the board of trustees and chair of the governance committee of SIR Royalty Income Fund (a TSX-listed public company).

“I am thrilled to welcome Sandra to the GFL board of directors, following an extensive search for a new independent director”, said Patrick Dovigi, Founder and CEO of GFL. “Sandra’s broad experience as a lawyer, an HR professional, and an Olympian allows her to bring a unique perspective to GFL’s Board.” Mr. Dovigi continued, “We look forward to drawing on Sandra’s experience as we continue to build a diverse and inclusive workforce at GFL that supports our entrepreneurial and innovative culture.”

About GFL

GFL, headquartered in Vaughan, Ontario, is the fourth largest diversified environmental services company in North America, providing a comprehensive line of solid waste management, liquid waste management and soil remediation services through its platform of facilities throughout Canada and in more than half of the U.S. states. Across its organization, GFL has a workforce of more than 19,500 employees.

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