British Leyland was an automotive engineering and manufacturing conglomerate formed in the United Kingdom in 1968 as British Leyland Motor Corporation Ltd (BLMC), following the merger of Leyland Motors and British Motor Holdings. It was partly nationalised in 1975, when the UK government created a holding company called British Leyland, later renamed BL in 1978. It incorporated much of the British-owned motor vehicle industry, which in 1968 had a 40% share of the UK car market, with its history going back to 1895. Despite containing profitable marques such as Jaguar, Rover, and Land Rover, as well as the best-selling Mini, BLMC had a troubled history, leading to its eventual collapse in 1975 and subsequent part-nationalisation.

Leyland Motors Limited was an English vehicle manufacturer of lorries, buses and trolleybuses. The company diversified into car manufacturing with its acquisitions of Triumph and Rover in 1960 and 1967, respectively. It gave its name to the British Leyland Motor Corporation, formed when it merged with British Motor Holdings in 1968, to become British Leyland after being nationalised. British Leyland later changed its name to simply BL, then in 1986 to Rover Group.