The 539th Fighter-Interceptor Squadron is an inactive United States Air Force unit. Its last assignment was with the 26th Air Division at McGuire Air Force Base, New Jersey, where it was inactivated on 31 August 1967. During World War II, the squadron was activated in 1943 as a Replacement Training Unit, and served until 1944 when it was disbanded when the Army Air Forces reorganized its training and support units in the United States. It was reactivated as a fighter interceptor unit in 1954, and served in that role, first with various models of the North American F-86 Sabre, then with the Convair F-106 Delta Dart until inactivating. (en)