X0306 4 2022-05-25 0000749251 GARTNER INC IT 0001198849 HALL EUGENE A 56 TOP GALLANT ROAD P.O. BOX 10212 STAMFORD CT 06904-2212 1 1 CEO Common Stock 2022-05-25 4 S 0 12081 250.00 D 1177443 D This transaction was executed in multiple trades at prices ranging from $250.00 to $250.05. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. /s/ Kevin Tang for Eugene A. Hall 2022-05-27