The F-35 Joint Strike Fighter ( JSF ) is a military fighter aircraft designed by the United States and the United Kingdom . It is intended to replace the current generation of strike fighters, particularly the vertical take off and landing (VTOL) Harrier jump jets : the AV-8 Harrier II (US), Harrier GR7/9 (UK), and the Sea Harrier (UK), along with the conventional A-10 Thunderbolt II, F/A-18 Hornet and the F-16 Fighting Falcon. It will be a multi-role strike fighter (a plane with a strong emphasis on close air support and tactical bombing as well as being capable of air-to-air combat), and will use stealth technology. It is currently in production with Lockheed Martin along with Northrop Grumman.

JSF is a joint, multinational acquisition program for the Air Force, Navy, Marine Corps, and eight cooperative international partners. Expected to be the largest military aircraft procurement ever, the stealth, supersonic F-35 Joint Strike Fighter (F-35) will replace a wide range of aging fighter and strike aircraft for the U.S. Air Force, Navy, Marine Corps and allied defense forces worldwide. The program's hallmark is affordability achieved through a high degree of aircraft commonality among three variants: conventional takeoff/landing (CTOL), carrier variant (CV) and short takeoff/vertical landing (STOVL) aircraft. Innovative concepts and advanced technologies will significantly reduce weapon system life-cycle costs while meeting the strike weapon system requirements of military customers.