Jaguar founder William Lyons recognised that racing success at Le Mans could elevate the brand internationally. The pre-existing XK120 road car, introduced in 1948 with a 3.4-litre twin-cam straight-six engine, provided a proven mechanical foundation from which competition variants could be developed. Frederick "Lofty" England managed the racing programme, and engineers including William Heynes, Bob Knight, and later aerodynamicist Malcolm Sayer — who had previously worked for the Bristol Aeroplane Company — designed the factory competition cars.
The Jaguar C-Type, officially the XK120-C, debuted at Le Mans in 1951 on its first attempt and won, driven by Peter Walker and Peter Whitehead. The car combined the XK engine with a lightweight tubular frame and an aerodynamic aluminium body. A disastrous 1952 attempt, in which modifications to improve top speed resulted in all three factory entries overheating and retiring, was followed by redemption in 1953: C-Types won and placed second and fourth, with Duncan Hamilton and Tony Rolt taking victory at an average of 105.85 mph — the first Le Mans win at over 100 mph. The 1953 cars used new disc brakes on all four wheels, an innovation whose advantage in the race prompted a rapid industry-wide adoption for production cars.
Jaguar built 53 C-Types in total, selling 43 to private customers, mainly in the United States.
The D-Type succeeded the C-Type from 1954, introducing monocoque construction and integrated aerodynamic technology drawn from aviation practice. Malcolm Sayer designed the body, which featured an optional vertical fin behind the driver for stability on Le Mans's long Mulsanne Straight. The XK engine was enlarged over the D-Type's life from 3.4 litres to 3.8 litres before a 3.0-litre limit for sports racers was introduced in 1958.
At the 1954 Le Mans, fuel filter problems necessitated unscheduled pit stops and Hamilton and Tony Rolt finished just under a lap behind the winning Ferrari, despite the D-Type's significantly higher top speed on the straight — 172.8 mph against the Ferrari's 160.1 mph. In 1955, Jaguar ran competitively against the Mercedes-Benz 300 SLRs until the catastrophic accident involving Pierre Levegh claimed more than 80 lives and destroyed eleven spectators. Mercedes withdrew from the race; Jaguar continued and Mike Hawthorn and Ivor Bueb won.
Jaguar withdrew from the factory programme at the end of the 1956 season. Despite this, 1957 proved the D-Type's most successful year: the small Edinburgh-based privateer team Ecurie Ecosse, running D-Types with substantial support from Jaguar, won Le Mans with Ron Flockhart and Ninian Sanderson, and D-Types took five of the first six places in the race.
Jaguar produced approximately 71 D-Types including 18 for works use and 53 for private customers. After the factory withdrew, the company converted remaining unfinished D-Types into the roadgoing XKSS. A fire at the Browns Lane factory on 12 February 1957 destroyed nine of the 25 cars in progress, ending XKSS production prematurely.
The Briggs Cunningham team raced D-Types extensively in America, winning the 1955 12 Hours of Sebring with Hawthorn and Phil Walters in a car on loan from the works.
The Jaguar works team of the 1950s is credited with five outright Le Mans victories: 1951 and 1953 with the C-Type, and 1955, 1956, and 1957 with the D-Type (the latter two through Ecurie Ecosse with strong factory support). The team's adoption of disc brakes in 1953 had a direct and lasting effect on the entire industry. The D-Type chassis also formed the basis for the Jaguar E-Type road car from 1961, making the competition programme directly influential on one of the most celebrated road cars in automotive history. Original racing D-Types have reached prices above $21 million at auction.