Waste Connections, Inc.

Item 1.01. Entry into a Material Definitive Agreement. On July 27, 2026, Waste Connections, Inc. (“Waste Connections” or the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with CIBC World Markets Inc., Scotia Capital Inc. and TD Securities Inc., and the several other underwriters named therein (collectively, the “Underwriters”), relating to the public offering (the “Offering”) by Waste Connections of C$300 million aggregate principal amount of its 4.200% Senior Notes due 2033 (the “2033 Notes”), and C$400 million aggregate principal amount of its 4.550% Senior Notes due 2036 (together with the 2033 Notes, the “Notes”). The Underwriting Agreement contains customary representations, warranties and agreements by the Company and customary conditions to closing, obligations of the parties and termination provisions. Additionally, the Company has agreed to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”), or to contribute to payments the Underwriters may be required to make because of any of those liabilities. The Offering has been registered under the Securities Act, pursuant to the Company’s Registration Statement on Form S-3ASR (File No. 333-282813), as supplemented by a prospectus supplement, dated July 27, 2026, relating to the Notes (together with the accompanying base prospectus, dated October 24, 2024, the “Prospectus Supplement”), filed with the Securities and Exchange Commission (the “SEC”) pursuant to Rule 424(b) of the Securities Act on July 27, 2026. The Offering is being made on a private placement basis in Canada to purchasers in each province of Canada under a Canadian offering memorandum, which includes the Prospectus Supplement. As more fully described under the caption “Underwriting (Conflicts of Interest)” in the Prospectus Supplement, from time to time, certain of the Underwriters and their affiliates have engaged in, and may in the future engage in, investment banking and other commercial dealings in the ordinary course of business with the Company or its affiliates. They have received, or may in the future receive, customary fees and commissions for these transactions. In addition, certain of the Underwriters or their affiliates serve various roles under the revolving credit facility provided for under the Company’s credit agreement, and, as a result, such Underwriters or their affiliates will indirectly receive a portion of the proceeds of the Offering. The summary of the Underwriting Agreement in this report does not purport to be complete and is qualified in its entirety by reference to the full text of the Underwriting Agreement, which is filed as Exhibit 1.1 hereto, and is incorporated herein by reference.

Item 7.01. Regulation FD Disclosure. On July 27, 2026, Waste Connections issued a press release announcing the launch of the Offering. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference. On July 27, 2026, Waste Connections issued a press release announcing the pricing of the Offering. A copy of the press release is furnished as Exhibit 99.2 hereto and is incorporated herein by reference. Safe Harbor and Forward-Looking Information This document contains forward-looking statements within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995 (“PSLRA”), including “forward-looking information” within the meaning of applicable Canadian securities laws. These forward-looking statements are neither historical facts nor assurances of future performance and reflect Waste Connections’ current beliefs and expectations regarding future events, including the completion of the Offering. These forward-looking statements are often identified by the words “may,” “might,” “believes,” “thinks,” “expects,” “estimate,” “continue,” “intends” or other words of similar meaning. All of the forward-looking statements included in this document are made pursuant to the safe harbor provisions of the PSLRA and applicable securities laws in Canada. Forward-looking statements involve risks, assumptions and uncertainties. Important factors that could cause actual results to differ, possibly materially, from those indicated by the forward-looking statements include, but are not limited to, risk factors detailed in the Prospectus Supplement and the accompanying base prospectus, which are both a part of the Registration Statement, the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025, and those risk factors set forth from time to time in the Company’s other filings with the SEC and the securities commissions or similar regulatory authorities in Canada. The closing of the Offering is subject to market conditions and a number of other conditions and approvals. The final terms may vary as a result of such market and other conditions. There can be no assurance that the Offering will be completed as described herein or at all. You should not place undue reliance on forward-looking statements, which speak only as of the date of this document. Waste Connections undertakes no obligation to update the forward-looking statements set forth in this document, whether as a result of new information, future events, or otherwise, unless required by applicable securities laws.