At the end of 2006, SEAT expanded the Altea family with the Altea XL, a vehicle for families who needed interior space and load capacity above all else. It retained the sporty and innovative design of the Altea, but with the size of a true family car.

SEAT had introduced a new vehicle concept to its range and to the market in general with the Altea, a compact MPV with character and sporty performance, which was launched in 2004.

Two and a half years later, in September 2006, SEAT unveiled the Altea XL at the Paris Motor Show. The new model went on sale in November. As the ‘XL’ in its name suggests, it was 18.7 centimetres longer than the Altea, with a longer rear overhang. At 4.46 metres long, it was tailored to the needs of families who appreciated the Altea's sporty image and dynamic appearance but needed more space.

This increased the boot capacity from 409 litres in the Altea to 532 litres in the Altea XL. In addition, the Altea XL offered the possibility of moving the rear seats forward by 14 centimetres, gaining 100 extra litres of boot space, up to 635 litres. It was the vehicle with the largest boot volume among its competitors, a capacity that could reach up to 1,604 litres if the rear seats were folded down.

The Altea XL's great versatility was also evident in another detail: the rear seats could be moved an additional two centimetres rearwards compared to the Altea, offering more legroom for rear passengers, while the boot still had a capacity of 517 litres. The total travel of the rear seats in the Altea XL was therefore 16 cm..

As for the front seats, like the Altea, the Altea XL stood out for its driving position, which was 80 millimetres higher than in a compact car such as the SEAT Leon. This was particularly appreciated by those who liked to travel in a higher position, and is now one of the main selling points of SUVs.

As a derivative of the Altea, the Altea XL also incorporated the Agile Chassis concept, which provided greater control and responsiveness, and therefore a significant increase in active safety. The result was that, despite its relatively high body, the Altea XL had astonishing turning speed and minimal body roll when cornering. All this was combined with ABS, TCS and ESP with brake assist. In terms of passive safety, the Altea XL could be fitted with up to eight airbags, as it also offered rear side airbags.

Aesthetically, the rear was where the differences from the Altea were most noticeable. The split rear lights, which occupied part of the tailgate, were particularly striking, giving the car a very elegant look. New features also included roof bars and larger rear-view mirrors.

Inside, the family car focus was evident, for example, in the trays on the front seat backs and the 12 V socket in the boot. And besides, of course, there were numerous storage compartments throughout the passenger compartment.

The range consisted of two petrol engines, a 1.6-litre 102 HP and a 2.0 FSI 150 HP (the latter with a 6-speed Tiptronic automatic transmission), and three diesel engines, a 1.9 TDI 105, a 2.0 TDI 140 (with optional DSG dual-clutch transmission) and a 2.0 TDI 170. The trim levels were Reference, Stylance and Sport-up.

The Altea family was further expanded in May 2007 with the launch of the Altea Freetrack at the Barcelona Motor Show. It was an SUV-style crossover based on the Altea XL, with a Haldex-type all-wheel drive system. It was clearly distinguished by large bumpers and protective mouldings on the black plastic wheel arches, and 40 mm higher ground clearance.

The Altea XL is also important in SEAT's history because it was the basis for SEAT's first electric vehicle built in a small series, culminating the work carried out at the Technical Centre since 1992, when the Toledo Electric prototype was created for the 1992 Barcelona Olympic Games. Called the Altea XL Electric Ecomotive (or e-Altea XL), it was unveiled on 9 November 2011. With a range of 135 km, five of the six units produced were donated to public administrations. A prototype Leon TwinDrive Ecomotive was also unveiled at the same time, in this case a plug-in hybrid.

In 2009, the Altea and Altea XL underwent a restyling, focusing on the headlamps, bumpers, seats and the central dashboard panel. In mid-2015, with the future Ateca, SEAT's first true SUV, already on the horizon, the Altea and Altea XL were discontinued.