The Jaguar Mark 1 is a British saloon car produced by Jaguar between 1955 and 1959. Referred to in contemporary company documentation as the Jaguar 2.4 Litre and Jaguar 3.4 Litre, the word "Saloon" was often added. The designation "Mark 1" was included retrospectively upon its replacement by the Mark 2 in October 1959. The 2.4 Litre was the company's first small saloon since the demise of its 1½ and 2½ Litre cars in 1949, and was an immediate success, easily outselling the larger Jaguar saloons.
The 2.4 Litre saloon was announced on 28 September 1955. The 3.4 Litre saloon announced 17 months later in USA on 26 February 1957 was designed for the American market and was not at first freely available on the domestic market.