The Supermarine Swift was a British single-seat jet-propelled fighter aircraft that was operated by the Royal Air Force (RAF). It was developed and manufactured by Supermarine during the 1940s and 1950s. The Swift featured many of the new jet age innovations, such as a swept wing. On 26 September 1953, an Swift F.4 piloted by Commander Mike Lithgow broke the world absolute speed record, reaching a speed of 737.7 mph (1,187 km/h); thus, the Swift held the distinction of being the world's fastest aircraft.

After a protracted development period, the Swift entered service as an interceptor aircraft with the RAF in 1954. However, due to a spate of accidents incurred by the type, the Swift was grounded for a time, and experienced a relatively brief service life. These issues with the Swift led to a public scandal surrounding the aircraft, harming the reputations of the British government, the RAF, and the aircraft industry.

Ultimately, the less problematic Hawker Hunter assumed much of the intended role for the type and only half as many Swifts ended up being manufactured as had once been intended. A later-produced photo reconnaissance variant of the Swift had resolved some of the teething problems that the type had suffered from, but this proved to be too late for it to regain favour. An advanced derivative of the Swift that was to be capable of transonic speeds, the Supermarine 545, was also under development during the early 1950s; however, in 1955, it was cancelled principally due to the poor performance of the Swift.

In February 1954, the Swift F 1 entered service with the RAF, No. 56 Squadron became the first RAF squadron to operate the type; upon its introduction, the Swift became the RAF's first swept-wing aircraft. The Swift F 2 entered service that same month; Wood refers to the type's introduction as having been "panicked", and that this adoption soon proved to be an "abysmal failure". Tragedy struck very early in the career of the Swift: there were a number of accidents that involved the F 1 and F 2, one of these being fatal. In August 1954, it was decided that the Swift F 1 would be grounded; the Swift F 2, which had effectively replaced the F 1 in that same month, was also soon grounded alongside it due to similar reasons.

The improved Swift F 3 and F 4 fighters were noted to have improved performance over their predecessors; the F 4 would be the last variant that the RAF would accept in the interceptor role. All fighter variants of the Swift were withdrawn from service by the RAF, after a short time in service, to be replaced by the more capable Hawker Hunter. While subject to its own problems, the Hunter had quickly proved to be a successful fighter aircraft.[10] By autumn 1954, the issues with the Swift had become public knowledge and reports of the pending cancellation of the Swift were being printed by the national press; Under-Secretary of State for Air Sir George Ward stated of the aircraft in Parliament that: "Aerodynamic difficulties have been encountered, and it is not possible to say with certainty if they can be overcome in version under development".

In early February 1955, the Swift was rumoured to have failed its final evaluation by the RAF Central Fighter Establishment, and that the type would likely be restricted in RAF service to aerial reconnaissance or to ground attack roles as a result. On 2 March 1955, Minister of Supply Selwyn Lloyd acknowledged that development of the Swift had cost £20 million prior to the scrapping of the fighter variants. According to Wood, the Swift had become a national scandal by early 1955, which not only tarnished the aircraft but also the RAF and the British aircraft industry, the public and ministers alike generally adopting a more adverse nature to aviation and other aircraft projects.

The FR.5 was the last Swift variant to enter service with the RAF and was eventually replaced by the Hunter FR.10, leaving RAF service entirely in 1961. The Swift FR 5 was deemed to be suitable for its role and was based with two squadrons that were assigned to RAF Germany. The Swift never saw combat action with the RAF. It did break a number of speed records in its time; in Libya, on 26 September 1953, an F.4 (WK198) piloted by Commander Mike Lithgow broke the world absolute speed record, reaching a speed of 737.7 mph (1,187 km/h), though it was broken in turn just eight days later by the Douglas Skyray, a United States Navy (USN) fighter. The Swift has the distinction of being the last British production aircraft to hold this record (the Fairey Delta 2 was experimental). Under two hundred Swifts were built from an order of 497. A number of Swift airframes went to Australia for Operation Buffalo in 1956, being placed at various distances from a detonating atomic bomb.

By its last variant many of the problems that had plagued earlier Swifts were resolved but the programme was not continued. The Hunter, performing satisfactorily in the same roles, removed any requirement to persist with the Swift.