The McDonnell Douglas F-4 Phantom II was one of the principal combat aircraft of the United Kingdom (UK) from 1968 to 1992. The UK was the first export customer for the US-built F-4 Phantom, which was ordered in the context of political and economic difficulties around British designs for similar aircraft. The Phantom was procured to serve in both the Royal Navy's Fleet Air Arm and the Royal Air Force (RAF) in several roles including air defence, close air support, low-level attack and tactical reconnaissance.
Most Phantoms operated by the UK were built as a special batch containing a significant amount of British technology. This was a means of supporting the British aerospace industry in the wake of major project cancellations. Two variants were initially built for the UK: the F-4K variant was designed from the outset as an air-defence interceptor to be operated by the Fleet Air Arm from the Royal Navy's aircraft carriers, and the F-4M version was procured for the RAF to serve in tactical strike and reconnaissance roles. In the mid-1980s, a third Phantom variant was obtained when fifteen second-hand F-4J aircraft were purchased to augment the UK's air defences following the Falklands War.
The Phantom entered service with both the Fleet Air Arm and the RAF in 1969. In Fleet Air Arm service, while primarily intended for fleet air defence, it had secondary conventional and nuclear strike roles, while in the RAF it was soon replaced in its initial tasks by other aircraft designed specifically for strike, close air support and reconnaissance, and instead was moved to the air-defence mission. By the mid-1970s, the Phantom had become the UK's principal interceptor; it continued in this role until 1992, when it was withdrawn as part of a series of post-Cold War defence cuts.