AC Cars Group Ltd. is a British specialist car manufacturing company and one of the oldest independent car marques in Britain. Based in Weybridge, Surrey (see also British motor industry).

It began as Weller Brothers in 1901, becoming Autocarriers Ltd in 1909 and using the 'AC' logo. The company moved to Thames Ditton, Surrey in 1911 and grew into a substantial car manufacturer. In 1930 the company was bought by the Hurlock family.

In 1951 the firm began production of the AC Ace, a lightweight chassis with a Bristol six-cylinder engine the car raced at Le Mans in 1957 and 1958. When the company lost access to the Bristol engine in 1961 the owner, Charles Hurlock, was approached by Carroll Shelby to use a Ford V8 in the Ace chassis, producing the AC Cobra in 1962. The Cobra was a dangerously over-powered roadster, its speed exploits were directly responsible for the introduction of the 70 mph limit on British motorways. The Cobra was sold to Ford in 1965 and production of the original ended in 1969.

The company was sold to Ford and Autokraft in 1986 and became AC Car Group. The group was sold again in 1993 and went into receivership in 1996 but was rescued from administration, as AC Car Group Ltd, and continued car production.