The Bristol F.2 Fighter is a British First World War two-seat biplane fighter and reconnaissance aircraft developed by Frank Barnwell at the British and Colonial Aeroplane Company later known as the Bristol Aeroplane Company. It is often simply called the Bristol Fighter, "Brisfit" or "Biff".

Although the type was intended initially as a replacement for the pre-war Royal Aircraft Factory B.E.2c reconnaissance aircraft, the new Rolls-Royce Falcon V12 engine gave it the performance of a fighter.

Despite a disastrous start to its career, the definitive F.2B version proved to be a manoeuvrable aircraft that was able to hold its own against single-seat fighters while its robust design ensured that it remained in military service into the early 1930s. Some war-surplus aircraft were registered for civilian use and versions with passenger cabins were converted.

In late 1915, the Royal Flying Corps (RFC) needed a new aerial reconnaissance and artillery spotting aircraft to replace the pre-war Royal Aircraft Factory B.E.2c. Among other attributes and performance requirements, emphasis was placed upon the ability to defend itself in aerial combat.

Several new types were developed; the Royal Aircraft Factory offered its R.E.8 design and Armstrong Whitworth produced the design that eventually emerged as the F.K.8. In March 1916, Frank Barnwell of the British and Colonial Aeroplane Company (later the Bristol Aeroplane Company), commenced work on a replacement for the B.E.2. This initially took two forms, the Type 9 R.2A, to be powered by the 120 hp Beardmore engine and the similar Type 9A R.2B, powered by the 150 hp Hispano-Suiza. Both designs had the fuselage mounted between the wings, with a gap between the lower longerons and the wing, along with a substantial part of the fin beneath the fuselage. These features were intended to improve the field of fire for the observer; the positioning of the fuselage also resulted in the upper wing obscuring less of the pilot's field of view. The crew positions were placed as close together as possible, to help communication between the pilot and observer.

Before either the R.2A or R.2B could be built, the new 190 hp (142 kW) Rolls-Royce Falcon inline engine became available. Barnwell drafted a third revision of his design around the new engine, with its decidedly superior power/weight ratio. The anticipated improvement in performance changed the emphasis in its intended operational use; it was now seen as a replacement for the F.E.2d and Sopwith 1½ Strutter two-seat fighters, rather than a competitor with the pedestrian reconnaissance designs that were to replace the B.E.2. The resulting Type 12 F.2A, was a two-bay equal-span biplane, closely based on the R.2A and R.2B designs.

In July 1916, work commenced on the construction of a pair of prototypes; on 28 August 1916, an initial contract was awarded for fifty production aircraft. On 9 September 1916, the first prototype performed its maiden flight, powered by a Falcon I engine. It was fitted with B.E.2d wings (Bristol were major contractors for the type) to save time; its lower wings were attached to an open wing-anchorage frame and had end-plates at the wing roots. On 25 October 1916, the second prototype was completed, powered by a Hispano-Suiza engine and differing from the first prototype in its tail-skid, which was integrated into the base of the rudder.

It was found that the prototype's radiator arrangement obscured the pilot's field of view and the nose was redesigned around a new circular-shaped frontal radiator in the cowling. Other changes made to the first prototype during flight testing included the elimination of the end-plates from the lower wing roots and the addition of a shallow coaming around the cockpits. Between 16 and 18 October 1916, the type underwent its official trials at the Central Flying School, Upavon, during which it was tested with a four-bladed 9 ft 2 in propeller and a two-bladed 9 ft 8 in propeller. By the time of its arrival at the experimental armament station at Orfordness it had also been fitted with a Scarff ring mounting over the rear cockpit and an Aldis optical sight.