FORM 10-K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIESEXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 ORTRANSITIONREPORT PURSUANT TO SECTION 13 OR 15(d)OF THESECURITIES EXCHANGE ACT OF 1934 Commission file number: 1-14443 Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of theSecurities Act. YesNo Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section15(d) of the Act. YesNo Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter periodthat the registrant was required to file such reports), and (2) has been subject to such filing requirementsfor the past 90 days. YesNo Indicate by check mark whether the registrant has submitted electronically every Interactive Data Filerequired to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during thepreceding 12 months (or for such shorter period that the registrant was required to submit such files).YesNo Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of“large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company”in Rule 12b-2 of the Exchange Act. Large accelerated filerAccelerated filerNon-accelerated filerSmaller reportingcompanyEmerging growth company If an emerging growth company, indicate by check mark if the registrant has elected not to use the extendedtransition period for complying with any new or revised financial accounting standards provided pursuant toSection 13(a) of the Exchange Act. Indicate by check mark whether the registrant has filed a report on and attestation to its management’sassessment of the effectiveness of its internal control over financial reporting under Section 404(b) of theSarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issuedits audit report. If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether thefinancial statements of the registrant included in the filing reflect the correction of an error to previouslyissued financial statements. Indicate by check mark whether any of those error corrections are restatements that required a recoveryanalysis of incentive-based compensation received by any of the registrant’s executive officers during therelevant recovery period pursuant to §240.10D-1(b). Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).YesNo As of June 30, 2024, the aggregate market value of the registrant’s common stock held by non-affiliatesof the registrant was $33.6 billion, based on the closing price as reported on the New York StockExchange. As of February 7, 2025, there were 76,818,191 shares of the registrant’s common stock outstanding. DOCUMENTS INCORPORATED BY REFERENCE The definitive Proxy Statement for the Annual Meeting of Stockholders (the“2025 Proxy Statement”) isincorporated by reference into Part III to the extent described therein. GARTNER, INC.2024 ANNUAL REPORT ON FORM 10-KTABLE OF CONTENTS ITEM 1.BUSINESS3ITEM 1A.RISK FACTORS7ITEM 1B.UNRESOLVED STAFF COMMENTS16ITEM 1C.CYBERSECURITY16ITEM 2.PROPERTIES17ITEM 3.LEGAL PROCEEDINGS17ITEM 4.MINE SAFETY DISCLOSURES (not applicable)17 ITEM 5.MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDERMATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES18ITEM 6.[RESERVED]18ITEM 7.MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION ANDRESULTS OF OPERATIONS18ITEM 7A.QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK30ITEM 8.FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA30ITEM 9.CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTINGAND FINANCIAL DISCLOSURE30ITEM 9A.CONTROLS AND PROCEDURES31ITEM 9B.OTHER INFORMATION31ITEM 9C.DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENTINSPECTIONS31 ITEM 10.DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE32ITEM 11.EXECUTIVE COMPENSATION32ITEM 12.SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS ANDMANAGEMENT AND RELATED STOCKHOLDER MATTERS32ITEM 13.CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS AND DIRECTORINDEPENDENCE32ITEM 14.PRINCIPAL ACCOUNTANT FEES AND SERVICES32 PART IVITEM 15.EXHIBITS AND FINANCIAL STATEMENT SCHEDULES33INDEX TO CONSOLIDATED FINANCIAL STATEMENTS35REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM36REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM38CONSOLIDATED BALANCE SHEETS39CONSOLIDATED STATEMENTS OF OPERATIONS40CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME41CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY42CONSOLIDATED STATEMENTS OF CASH