UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number 1-14443 Gartner, Inc. (Exact name of Registrant as specified in its charter) Delaware 04-3099750 (State or other jurisdiction of (I.R.S. Employer incorporation ...