John B. McKay (December 8, 1922 – April 27, 1975) was one of the first pilots assigned to the X-15 flight research program at NASA's Flight Research Center, Edwards Air Force Base, California. As a civilian research pilot and aeronautical engineer, he made 30 flights in X-15s from October 28, 1960, until September 8, 1966. His peak altitude was 295,600 feet, and his highest speed was 3,863 mph (Mach 5.64).
In addition to the X-15, he flew such experimental aircraft as the D-558-1, D-558-2, X-lB, and the X-lE. He has also served as a research pilot on flight programs involving the F-100, F-102, F-104, and the F-107.