[9] Jaguar invited Jay Leno to unveil the new XJ during the launch at the Saatchi Gallery in London on 9 July 2009.

[15] From 2014, assembly from complete knockdown kits, or CKD, of the XJ commenced at Jaguar Land Rover's facility in Pune, India.

[10] At the 2010 Moscow Motor Show, a high security version of the car called the XJ Sentinel was introduced.

It has the 5.0 L supercharged V8 engine shared with the XJ Supersport having a power output of 510 PS (375 kW) and 19-inch wheels with Dunlop Self Supporting Technology run-flat tyres.

[23] Unlike other full-size flagship executive cars, the long-wheelbase variant was designed first and was expected to make up 67 percent of sales in the US market.

[28] The XJ features a lightweight aluminium floorpan and body (with 50% recycled material content) based on the X350 chassis and retaining a proportion of the earlier floor pan.

[29] Standard equipment levels on the United States-spec XJ L with the base engine includes a panoramic dual-pane moonroof, lane-departure warning, navigation, quad-zone climate control, and power sunshades, which is considered to be generous at this price point compared to other flagship executive saloons.

Available only in the long wheelbase configuration, the car was developed by the Jaguar Land Rover's specialist Engineered To Order (ETO) division and was unveiled at the 2012 Beijing Auto Show.

Mechanical equipment for the US model includes a 5.0 L supercharged V8 engine rated at 510 PS (375 kW) and an eight-speed automatic transmission.

Available in standard and long wheelbase configurations, it includes a 5.0-litre supercharged V8 engine rated at 550 PS (405 kW; 542 hp) and 680 N⋅m (502 lb⋅ft), an increased top speed to 280 km/h (174 mph), eight-speed automatic transmission with a bespoke tuning for the XJR, a new front splitter and aerodynamic sill section combined with an additional rear spoiler and unique R bonnet louvres, Electronic Active Differential and Dynamic Stability Control systems calibrated to enhance handling characteristics, new 20-inch Farallon forged alloy wheels with bespoke Pirelli low-profile tyres, semi-aniline leather, a choice of veneers, and contrasting stitching on the seats.

On 30 May 2019, Autocar reported that Jaguar would discontinue the X351 in July 2019, partly to make way for a new flagship XJ electric car planned to be built at Castle Bromwich.

[51] The company said: "Following a thorough technology review against the exponential change in the automotive industry, we concluded that the planned XJ replacement does not fit with our vision for a reimaged Jaguar brand.