The Fox was the final development of the scout car design that began with the Dingo and Ferret, but considerably upgunned to make it a proper armored reconnaissance vehicle. The Fox went for an all-welded aluminum hull and turret in place of steel but otherwise borrows the same chassis design and configuration. The main change compared to the Ferret was the inclusion of a larger turret that mounts the then-new 30-mm L21 RARDEN autocannon. This can fire APDS and APSE rounds (as well as conventional high-explosive rounds) giving it a degree of combat capability against other armored vehicles that earlier scout cars lacked. Additionally, a 7.62-mm L37A2 machine gun is mounted coaxially. Unlike early Ferret variants, the Fox features NBC protection but amphibious capability is also absent even though it can be prepared for fording with the use of a floation screen. It is also air-transportable with up to three fitting inside a C-130 or two if paradropped. Unlike the highly successful Ferret, the Fox was produced only in small numbers with export orders coming only from Malawi and Nigeria. This was largely due to the superior performance of tracked ARVs that were introduced around the same time such as the Scorpion, many of which were mated with the Fox turret resulting in the Sabre ARV.

Development of the Fox (FV721) began in 1965 with the first prototype ready in 1967. It was to be the first in a family of vehicles known as the Combat Vehicle Reconnaissance (Wheeled) or CVR(W) which also included a cancelled turret-less version known as the Vixen (FV722). No major variants were built although various resdesigns were proposed. After its retirement, Fox turrets were removed and installed on the chassis of the Scorpion which resulted in the Sabre (described in the Scorpion entry).