EX-32.1 4 wcn-20250930xex32d1.htm EX-32.1

Exhibit 32.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

(Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code)

I, Ronald J. Mittelstaedt, being the duly elected and acting President and Chief Executive Officer of Waste Connections, Inc., a corporation organized under the laws of Ontario, Canada (the “Company”), hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge:

| 1. | The Quarterly Report of the Company on Form 10-Q for the period ended September 30, 2025 (the “Report”), fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

| 2. | The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

9 |  |
Date: October 22, 2025 | By: | /s/ Ronald J. Mittelstaedt
|  | Ronald J. Mittelstaedt
|  | President and Chief Executive Officer

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The foregoing certification is being furnished solely to accompany the Report pursuant to 18 U.S.C. Section 1350, and shall not be deemed filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and shall not be deemed to be incorporated by reference into any filing of the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing, except to the extent that the Company specifically incorporates it by reference.