The Jaguar Mark X (pronounced mark ten) was the top-of-the-range saloon car built by the British manufacturer Jaguar from 1961 to 1970, originally aimed at the United States market. The Mark X succeeded the Mark IX as the company's large saloon model.
The modern Jaguar face, four headlamps set into rounded front fenders with a vaned grill, first appeared on the Mark X. The interior is the last Jaguar with abundant standard woodwork, including the dashboard, escutcheons, window trim, a pair of large bookmatched fold out rear picnic tables, and a front seat pull-out picnic table stowed beneath the instrument cluster. Over time, air conditioning and a sound-proof glass division between the front and rear seats were added as options.
The Mark X was the first Jaguar saloon to feature independent rear suspension. Front suspension used double wishbones with coil springs and telescopic dampers. Initially Jaguar's XK in-line six-cylinder engine was featured, with 3781 cc. A 9:1 compression ration was standard, but an alternative 8:1 compression ratio was available as an option. Transmission options were manual, manual with overdrive or automatic. The arrival of the 4.2-litre power unit coincided with the introduction of a newly developed all-synchromesh four-speed gear box replacing the venerable box inherited by the 3.8-litre Mark X from the Mark IX which had featured synchromesh only on the top three ratios. Many domestic market cars and almost all cars destined for the important North American markets left the factory with a Borg Warner automatic gear-box.
From its introduction until the arrival in 1992 of the low-slung XJ220, the Mark X stood as one of the widest production Jaguars ever built.