The AV-8B was developed as a second-generation Harrier, primarily for the US Marine Corps. The Harrier II entered USMC service in 1984 and participated extensively in the 1991 Gulf ധąɾ. This aircraft is routinely deployed onboard amphibious assault ships.

The Harrier II fleet, which equips seven operational squadrons, has gone through two avionics upgrades to the baseline version, and through a re-manufacturing programme. A night-attack sensor upgrade equips four squadrons. The Harrier II+, which incorporates the night-attack upgrades and the APG-65 multi-mode radar, equips two squadrons.

A re-manufacture programme was intended for 72 aircraft and involved replacement of the Pegasus F402-RR-406 engine with the increased-thrust -408A version. The upgrade also included APG-65 radar, a navigation infra-red set, night vision goggles-compatible cockpit, exterior lighting, and a moving-map display.

AV-8Bs are also going through an avionics upgrade with fitment of a GPS, the common missile approach warning system, frequency-agile digital radios, and the digital Advanced Target Hand-off System, and all are gaining the ability to deploy JDAMs. The US is trying to fund an advanced targeting infra-red set for the Harrier. The two-seat TAV-8B, used by the Harrier training squadron, was also upgraded with the F402-RR-408A engine.

The first foreign operator was the Spanish navy which received 12 EAV-8Bs, eight AV-8B Plus and a single EV-8B trainer for operation from the carrier Principe de Asturias. The Flotilla de Aeronaves is having its nine surviving EAV-8Bs converted to the Plus standard. Italy’s Marina Militare bought 18 AV-8B Harrier II Plus, including two two-seaters, for operation from the carrier Giuseppe Garibaldi. The Harriers of both navies are primarily tasked with fleet defense of their respective carriers, and have recently gained AIM-120B AMRAAM missile armament.