The Swallow Sidecar Company was founded in 1922 by two motorcycle enthusiasts, William Lyons and William Walmsley. In 1934, Walmsley elected to sell-out and in order to buy the Swallow business (but not the company which was liquidated) Lyons formed SS Cars, finding new capital by issuing shares to the public.

Jaguar first appeared in September 1935 as a model name on an SS 2½-litre sports saloon. A matching open two seater sports model with a 3½-litre engine was named SS Jaguar 100.

On 23 March 1945, the S. S. Cars shareholders in general meeting agreed to change the company's name to Jaguar Cars Limited. Said chairman William Lyons "Unlike S. S. the name Jaguar is distinctive and cannot be connected or confused with any similar foreign name."