The Jaguar XJ-S (later the Jaguar XJS) is a luxury grand tourer produced by the British manufacturer Jaguar. The XJ-S replaced the legendary E-Type (or XK-E) in September 1975, and was based on the XJ saloon. It had been developed as the XK-F, though it was very different in character from its predecessor. Although it never had quite the same sporting image, the XJ-S was a competent grand tourer, and more aerodynamic than the E-Type[citation needed]. The last XJS was produced on 4 April 1996, with the XK8 taking its place.

The first XJ-S appeared in 1975 as a 1976 model. Power came from the Jaguar V-12 petrol engine with a choice of a manual or automatic transmission, but the manual was soon dropped. V-12 automobiles were unusual at the time, with notable others coming from Italian luxury sports car makers Lamborghini and Ferrari. The specifications of the XJ-S compared well with both Italian cars; it was able to accelerate to 60mph (97km/h) in 8.9 seconds and reach 142mph (229km/h). The first series of XJ-S cars had a Borg-Warner Model 12 transmission with a cast iron case and a bolt-on bell-housing. In 1979 GM Turbo-Hydromatic 400 transmissions were fitted. The TH400 transmission was an all aluminium alloy case with an integrated non-detachable bell-housing.

Jaguar's timing was not good; the car was launched in the wake of a fuel crisis, and the market for a 5.3-litre V12 grand tourer was very small. The styling was also the subject of criticism, including the "flying buttresses" behind the windows.