Fruehauf Trailer Corporation, previously Fruehauf Trailer Company (1918–1963) and Fruehauf Corporation (1963–1989), was an American company engaged in the manufacture and sale of truck trailers, and other machinery and equipment, with headquarters located in Detroit, Michigan. It was founded in 1918 in Detroit, after August Fruehauf created the semi-trailer and launched a new industry. The Fruehauf trailer company introduced revolutionary inventions to trucking and transportation with hydraulic dump trailers, bulk tanker trailers, and automatic fifth-wheel couplings among their more than one thousand patents, including the shipping container in 1956. Expanding across the country, Fruehauf had 16 plants and more than 80 distributorships for parts and service. Globally, the company expanded into Europe, South America, and Asia.

A semi-trailer is a trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a semi-trailer truck.