Body-on-frame is a traditional motor vehicle construction method whereby a separate body or coach is mounted on a strong and relatively rigid vehicle frame or chassis that carries the powertrain and to which the wheels and their suspension, brakes, and steering are mounted. While this was the original method of building automobiles, body-on-frame construction is now used mainly for pickup trucks, large SUVs, and heavy trucks.

A coachbuilder or body-maker is a person or company who manufactures bodies for passenger-carrying vehicles. Coachwork is the body of an automobile, bus, horse-drawn carriage, or railway carriage. The word "coach" was derived from the Hungarian town of Kocs. A vehicle body constructed by a coachbuilder may be called a "coachbuilt body" or "custom body".