The Gulfstream II/SP (G-II/SP) is an American twin engine business jet designed and built by Grumman and then in succession, Grumman American and finally Gulfstream American. Its Grumman model number is G-1159 and its US military designation is C-11 Gulfstream II. It has been succeeded by the Gulfstream III. The first Gulfstream II flew on October 2, 1966.

The Gulfstream II/SP is a twin-engined executive, corporate transport aircraft, with accommodation for up to 14 passengers, powered by two Rolls-Royce Spey RB.168 Mk 511-8 turbofan engines. It received its FAA Type Certificate A12EA on October 19, 1967. Production began in 1967 and continued through the late 70s, with a total of 258 aircraft built. The Gulfstream II SP is the Gulfstream II modified by the addition of Aviation Partners winglets. It was FAA certified under STC ST00080SE on April 22, 1994.