Founded as the Swallow Sidecar Company in 1922, by two motorcycle enthusiasts, William Lyons and William Walmsley, the SS Jaguar name first appeared on a 2.5 litre saloon in 1935. The Jaguar name was given to the entire company in 1945.

Jaguar made its name in the 1950s with a series of elegantly-styled sports cars and luxury saloons. The company bought the Daimler car company (not to be confused with Daimler-Benz), in 1960 from Birmingham Small Arms Company (BSA). From the late 1960s, Daimler was used as a brand name for Jaguar's most luxurious saloons.
Jaguar merged with the British Motor Corporation (BMC), the Austin-Morris combine, to form British Motor Holdings (BMH) in 1966. After merging with Leyland and Rover, the resultant company then became British Leyland Motor Corporation (BLMC) in 1968. Financial difficulties and the publication of the Ryder Report led to effective nationalisation in 1975 and the company became BL Ltd (BL).

In 1984, Jaguar was floated off as a separate company on the stock market - one of the Thatcher government's many privatisations. The Ford Motor Company made an offer to purchase the company in September 1989 which was accepted at an Extraordinary General Meeting in January 1990 and Jaguar was removed from the London Stock Exchange listings on 28 February 1990. In 1999 it became part of Ford's new Premier Automotive Group along with Aston Martin, Volvo Cars and, from 2000, Land Rover; Aston Martin was subsequently sold off in 2007. Since Ford purchased Jaguar in 1989 it has yet to earn a profit for the Dearborn-based auto manufacturer.

Jaguar cars gained a reputation for unreliability during the 1970s and 1980s, but under Ford the reliability and build quality improved dramatically, with the company coming 7th (out of 30) in the J. D. Power Customer Satisfaction Survey (the '242-million mile road test'), and the S-Type coming 9th out of 105 cars in the same survey. In the 2003 Top Gear Survey, the XJ8 (X308) model came first. However, in 2007, another survey showed Jaguar to be one of the three least reliable brands.
The company was originally located in Blackpool but moved to Coventry in 1928 when demand for the Austin Swallow became too great for the factory's capacity. Today, Jaguars are assembled at Castle Bromwich in Birmingham and Halewood in Liverpool. The historic Browns Lane plant closed in 2005, leaving the XJ, XK and S-Type production at Castle Bromwich and the X-Type at Halewood, alongside the new Land Rover Freelander 2, from 2007.

Since Land Rover's 2002 purchase by Ford, it has been closely associated with Jaguar. In many countries they share a common sales and distribution network (including shared dealerships), and some models now share common components, although the only shared production facility is Halewood, for the X-Type and the Freelander 2.
On 11 June 2007, Ford announced that it planned to sell Jaguar, along with Land Rover. The buyer was initially expected to be announced by September 2007, possibly a private equity group, but the sale was delayed, and an announcement will not be made until the end of 2007. India's Tata Motors and Mahindra and Mahindra have expressed an interest in purchasing Jaguar and Land Rover from the Ford Motor Company. Ford has also announced that Volvo will be sold before the winter of 2007, finally dissolving the Ford PAG group.

Jaguar Cars holds Royal Warrants from both HM Queen Elizabeth II and HRH Prince Charles.

The Jaguar company started production with the pre-war 1.5, 2.5 and 3.5 litre models which used engines designed by the Standard Motor Company. The 1.5 litre four-cylinder engine was still supplied by Standard but the two larger six-cylinder ones were made in house. These cars have become known unofficially as Mark IVs.
The first post war model was the 1948 Mark V available with either 2.5 or 3.5 litre engines and had a more streamlined appearance than pre-war models, but more important was the change to independent front suspension and hydraulic brakes.

The big breakthrough was the launch in 1948 of the XK120 sports car, with the new XK twin overhead camshaft (DOHC) 3.5 litre hemi-head six-cylinder engine designed by William Heynes, Walter Hassan and Claude Baily. This engine had been designed during the long nights during the war when they would be on fire watch in the factory. After several attempts a final design was arrived at. That is until owner William Lyons said "make it quieter". The car had originally been intended as a short production model of about 200 vehicles as a test bed for the new engine until its intended home, the new Mark VII saloon, was ready. The XK120's reception was such that production continued until 1954; it was followed by the XK140, the XK150, and the E-Type, keeping Jaguar in the sports car market.

Introducing the large Mark VII saloon in 1951, a car especially conceived for the American market, Jaguar soon found itself overwhelmed with orders. The Mark VII and its successors gathered rave reviews from magazines such as Road & Track and The Motor. In 1956 a Mark VII won the prestigious Monte Carlo Rally.

The 1955 Mark 1 small saloon was the first monocoque (unibody) car from Jaguar and used a 2.4 litre short stroke version of the XK engine. In 1959, the car was improved with a larger engine and wider windows and became the Mark 2, one of the most recognizable Jaguar models ever produced. It would be popular with British police forces for its small size, light weight, and powerful engine.

The Mark VIII of 1956 and Mark IX of 1958 were essentially updates of the Mark VII but the Mark X of 1961 was a completely new design of large saloon with all round independent suspension and unibody construction.

The independent rear suspension from the Mark X was incorporated in the 1963 S-Type which closely resembled the Mark 2, and in 1967 the Mark 2 name was dropped when the small saloon became the 240/340 range. The 420 of 1966, also sold as the Daimler Sovereign, put a new front onto the S-type, although both cars continued in parallel until the S-Type was dropped in 1968. The Mark X became the 420G in 1966.

Of the more recent saloons, the most significant is the XJ (1968-present), still the definitive Jaguar saloon car for many. Since 1968 the Series I XJ has seen major changes in 1973 (to Series II), 1979 (Series III), 1986 Europe / 1987 United States (XJ40), 1995 (X300), 1997 (to the V-8 powered X308), 2003 (the present model, X350). The most luxurious XJ models carry either the Vanden Plas (US) or Daimler (rest of world) nameplates.