Harley-Davidson Motor Company is an American manufacturer of motorcycles based in Milwaukee, Wisconsin. The company sells heavyweight (over 750 cc) motorcycles designed for cruising on the highway. Harley-Davidson motorcycles (popularly known as "Harleys") have a distinctive design and exhaust note. They are especially noted for the tradition of heavy customization that gave rise to the chopper-style of motorcycle.

Harley-Davidson attracts a loyal brand community, with licensing of the Harley-Davidson logo accounting for almost 5% of the company's net revenue ($41 million in 2004). Harley-Davidson supplies many American police forces with their motorcycle fleets.

In 2003, the Buell Motorcycle Company became a wholly-owned subsidiary of Harley-Davidson, the same year that Harley-Davidson celebrated its 100th birthday. In August 2008, Harley-Davidson purchased the Italian motorcycle manufacturer MV Agusta.