W. O. Bentley's pre-war work selling French DFP cars in Cricklewood and his wartime observation that aluminium could replace cast iron for pistons — first applied to Sopwith Camel aero engines — provided the technical foundations. Bentley Motors was formally incorporated on 18 January 1919. The first car's 3-litre engine featured an overhead camshaft designed by ex-Royal Flying Corps officer Clive Gallop. The company made its international debut at the 1922 Indianapolis 500, where Douglas Hawkes completed all 500 miles from 19th on the grid to finish 13th.
The defining period of Bentley's motorsport identity was the late 1920s, when the Bentley Boys — a group of wealthy private enthusiasts — delivered four consecutive victories at the 24 Hours of Le Mans, 1927 through 1930. Key figures included Woolf Barnato, who rescued the company financially in 1926 and raced it competitively; Sir Henry "Tim" Birkin; and S. C. H. "Sammy" Davis. The cars evolved from the original 3-Litre through the 4½-Litre and the Speed Six, the last of which achieved a 1-2-3-4 finish in 1929 and a 1-2 in 1930. Bugatti, Bentley's principal rival, is said to have called the British cars "the world's fastest lorries." Bentley withdrew from racing after 1930 citing that it had "learned enough about speed and reliability."
The Great Depression eliminated the market for expensive cars. In July 1931 the company could not service two mortgage payments and a receiver was appointed. Rolls-Royce, operating through a front entity called British Central Equitable Trust, submitted the winning sealed bid of £125,000 — the purchaser's identity unknown to Bentley himself until the deal was finalised. Napier, which had expected to complete its own purchase, was outmanoeuvred.
Rolls-Royce formed Bentley Motors (1931) Ltd, suspended production for two years, and restarted at its Derby works. The resulting Bentley 3½ Litre of 1933 was a sporting variant of the Rolls-Royce 20/25 — described by Rolls-Royce advertising as "the silent sports car." W. O. Bentley himself departed for Lagonda at the end of April 1935. All Bentleys manufactured between 1931 and 2004 used Rolls-Royce derived chassis and engines.
To support wartime aero-engine production, a shadow factory was built at Crewe beginning July 1938 on 60 acres of farmland. The facility produced 25,000 Rolls-Royce Merlin aero-engines and employed 10,000 workers at peak in 1943. Following the war, motor car production transferred from Derby to Crewe. The first complete Bentley with a standard steel body — the Mark VI — entered production at Crewe in early 1946. The R Type Continental, produced from 1952, was a limited-volume fastback primarily bodied by H. J. Mulliner, with approximately 164 cars completed.
Financial difficulties at Rolls-Royce stemming from the RB211 aero-engine programme forced the company into receivership in 1970. The car division, separated as Rolls-Royce Motors Limited, was purchased by Vickers plc in August 1980. By that time Bentley's share of combined output had fallen below 5 percent. Vickers invested in recovering the high-performance image: the 1980 Mulsanne and the turbocharged Turbo R drew buyers back, and by 1991 Bentley and Rolls-Royce had reached production parity.
In October 1997 Vickers announced the sale of Rolls-Royce Motors. BMW, an existing engine and component supplier, bid £340 million. Volkswagen outbid at £430 million, acquiring designs, nameplates, facilities, and the Spirit of Ecstasy and grille shape trademarks but not the Rolls-Royce name or logo, which were separately licensed by BMW for £40 million to establish Rolls-Royce Motor Cars at Goodwood. Volkswagen modernised the Crewe factory and launched the Continental GT, Flying Spur, and Bentayga, with China growing to become Bentley's largest market by November 2012. From 2022, Bentley has been consolidated within Volkswagen Group under the Audi premium brand umbrella.
Bentley returned to factory competition at the 24 Hours of Le Mans and won the overall race in 2003. In GT3 racing, the Continental GT3 — a rear-wheel-drive racing derivative developed with M-Sport — was entered from 2013. A Continental GT3 won the Silverstone round of the 2014 Blancpain Endurance Series, representing Bentley's first official race entry on British soil since the 1930 RAC Tourist Trophy.