The Citroën CX is a large, front-engined, front-wheel-drive executive car manufactured and marketed by Citroën from 1974 to 1991. Production models were either a standard wheelbase or a stretched, more luxurious, four-door fastback saloon, as well as a station wagon (estate), on the longer wheelbase. The CX is known for its hydropneumatic self-leveling suspension system, and its low 0.36 drag coefficient, normally noted as a vehicle's in French. Restyled as 'CX', the model name underscored this.

A fastback is an automotive styling feature, defined by the rear of the car having a single slope from the roof to the tail.