The Jaguar Mark 1 is a British saloon car produced by Jaguar between 1955 and 1959. It was referred to in contemporary company documentation as the Jaguar 2.4 Litre and Jaguar 3.4 Litre. Its designation as Mark 1 was retroactive, following its October 1959 replacement by Jaguar's 2.4-litre Mark 2. The 2.4 Litre was the company's first small saloon since the end of its 1½ and 2½ Litre cars in 1949, and was an immediate success, easily outselling the larger much more expensive Jaguar saloons.

Jaguar is the sports car and luxury vehicle brand of Jaguar Land Rover, a British multinational car manufacturer with its headquarters in Whitley, Coventry, England. Jaguar Cars was the company that was responsible for the production of Jaguar cars until its operations were fully merged with those of Land Rover to form Jaguar Land Rover on 1 January 2013.