A sedan or saloon is a passenger car in a three-box configuration with separate compartments for an engine, passengers, and cargo. The first recorded use of sedan in reference to an automobile body occurred in 1912. The name derives from the 17th-century litter known as a sedan chair, a one-person enclosed box with windows and carried by porters. Variations of the sedan style include the close-coupled sedan, club sedan, convertible sedan, fastback sedan, hardtop sedan, notchback sedan, and sedanet.

The configuration of a car body is typically determined by the layout of the engine, passenger and luggage compartments, which can be shared or separately articulated. A key design feature is the car's roof-supporting pillars, designated from front to rear of the car as A-pillar, B-pillar, C-pillar and D-pillar.