The Charioteer Tank, or FV4101 Tank, Medium Gun, Charioteer was a post-world-war II British armoured fighting vehicle. It was produced in the 1950s to up-gun units of the Royal Armoured Corps continuing to use the Cromwell tank during the early phases of the Cold War. The vehicle itself was a modified Cromwell with a more powerful gun installed in a relatively lightly armoured two-man turret.

The Cromwell tank, officially Tank, Cruiser, Mk VIII, Cromwell (A27M), was one of the series of cruiser tanks fielded by Britain in the Second World War. Named after the English Civil War-era military leader Oliver Cromwell, the Cromwell was the first tank put into service by the British to combine high speed from a powerful, reliable engine and reasonable armour. The intended dual-purpose high velocity gun could not be fitted in the turret, so a medium velocity dual purpose gun was fitted instead. Further development of the Cromwell combined with a high velocity gun led to the Comet tank.