The Rolls-Royce Meteor later renamed the Rover Meteor is a British tank engine that was developed during the Second World War. It was used in British tanks up to 1964. It was a result of co-operation between Leyland Motors and Rolls-Royce who between them in 1941 had suggested that a specialised de-rated version of the Merlin aero-engine would be highly suitable for use in armoured fighting vehicles.

The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litre capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was later called Merlin following the company convention of naming its four-stroke piston aero engines after birds of prey. The engine benefitted from the racing experiences of precursor engines in the 1930s.