An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically to prevent successful missions by enemy aircraft, particularly bombers and reconnaissance aircraft. There are two general classes of interceptor: relatively lightweight aircraft built for high performance, and heavier aircraft designed to fly at night or in adverse weather and operate over longer ranges.

For daytime operations, conventional fighters normally fill the interceptor role, as well as many other missions. Daytime interceptors have been used in a defensive role since the World War I era, but are perhaps best known from several major actions during World War II, notably the Battle of Britain where the Supermarine Spitfire and Hawker Hurricane developed a good reputation. Few aircraft can be considered dedicated daytime interceptors, with the obvious exception for example of the Messerschmitt Me 163, and to a lesser degree designs like the Mikoyan-Gurevich MiG-15 which had heavy armament specifically intended for anti-bomber missions.

Night fighters and bomber destroyers are, by definition, interceptors of the heavy type, although initially they were rarely referred to as such. In the early Cold War era the combination of jet-powered bombers and nuclear weapons created air forces' demand for highly capable interceptors; it is during this period that the term is perhaps most recognized and used. Examples of classic interceptors of this era include the F-106 Delta Dart, Sukhoi Su-15 and English Electric Lightning. Through the 1960s rapid improvements in design led to most fighters having the performance to take on the interceptor role, and the strategic threat moved from bombers to intercontinental ballistic missiles (ICBMs). Dedicated interceptor designs became rare, with the only widely used examples designed after the 1960s being the Tornado F3 and Mikoyan MiG-31.