The Harrier, informally referred to as the Jump Jet, is a family of military jet aircraft capable of vertical/short takeoff and landing (V/STOL) operations. Historically the Harrier was developed in Britain to operate from ad-hoc facilities such as car parks or forest clearings, avoiding the need for large air bases vulnerable to tactical nuclear weapons. Later the design was adapted for use from aircraft carriers. The Harrier is also distinct as being of modern era, yet subsonic, contrasting with most of the major Western post-World War II-era attack aircraft, which tend to be supersonic.

There are two generations of four main variants of the Harrier family:

The Hawker Siddeley Harrier is the first generation-version and is also known as the AV-8A Harrier. The Sea Harrier is a naval strike/air defence fighter. The AV-8B and BAE Harrier II are the US and British variants respectively of the second generation Harrier aircraft.