Crossley Motors was an English motor vehicle manufacturer based in Manchester, England. It produced approximately 19,000 cars from 1904 until 1938, 5,500 buses from 1926 until 1958, and 21,000 goods and military vehicles from 1914 to 1945.

Crossley Brothers, originally manufacturers of textile machinery and rubber-processing plant, began the licensed manufacture of the Otto internal combustion engine before 1880. The firm started car production in 1903, building around 650 vehicles in their first year.

The company was established as a division of engine builders Crossley Brothers, but from 1910 became a stand-alone company. Although founded as a car maker, they were major suppliers of vehicles to British Armed Forces during World War I, and in the 1920s moved into bus manufacture. With rearmament in the 1930s, car production was scaled back and halted completely in 1936. During World War II, output was again concentrated on military vehicles. Bus production resumed in 1945, but no more cars were made. The directors decided in the late 1940s that the company was too small to survive on its own and agreed to a takeover by AEC. Production at the Crossley factories finally stopped in 1958.

Crossley Motors Ltd was first registered on 11 April 1906 (and re-registered with a different company number in 1910) as the vehicle manufacturing arm of Crossley Brothers. The first car was actually built in 1903 to a design by James S. Critchley, who had been with Daimler and exhibited at the Society of Motor Manufacturers' Exhibition at Crystal Palace in February 1904, but the parent company saw a future for these new machines and decided a separate company was required.

Critchley left the company in 1906 and was replaced by the team of Walter James Iden, A. W. Reeves and Hubert Woods who introduced the 12-14 hp (later 15 hp) and 20 hp models ^{[citation needed]}

In 1920, Crossley Motors bought 34,283 (68.5%) of the 50,000 issued shares of the nearby firm of Avro. Crossley took over Avro's car manufacturing business and Avro continued its aircraft manufacturing operations independently. In 1928, Crossley had to sell its shares in Avro to Armstrong Siddeley to pay for the losses incurred by the Willys Overland Crossley venture.

After World War II, the directors decided that the company was not large enough to prosper and looked for a partner. This resulted in a take over by Associated Equipment Company (AEC) in 1948. AEC's parent company changed its name to Associated Commercial Vehicles and Crossley became a division of it. Production of the Crossley range of vehicles continued at the Stockport plant until 1952. After that date, production turned to badge-engineered AEC designs and bus bodywork, until the factory was closed in 1958 and sold in 1959.

Although no longer trading, the company was never formally wound up. In 1969, AEC's new owner, British Leyland, restarted the company with a new name – Leyland National – and production of single-decker buses recommenced.