The Mk1 SEAT León hatchback (codename Typ 1M) launched in 1999,[3] and was produced at Martorell, with a small number of 13,401 cars assembled in Belgium.

To reinforce this image it had a fastback design inspired by the Alfa Romeo Alfasud, and used firmer suspension with wider tyres to improve handling.

The original Cupra was only available in the red, yellow and black colors of the Spanish and German national flags, as a homage to these countries collaborating on this project.

In June 2006 the León received the 147 kW (200 PS; 197 bhp) 2.0 TFSI engine from the Volkswagen Golf Mk5 GTI, with twin chrome exhaust pipes, sport seats, stiffer suspension, climate control and FR branded parts.

Unique Cupra parts included 18" 5 twin-spoke alloys, red brake calipers, oval exhaust, aluminium pedals, paint colours and heavily bolstered sports seats.

[citation needed] SEAT México announced the production of 100 units of the Copa Edition in orange colour with black stripes in September 2008.

[28] SEAT Nederland announced the production of León Cupra 310 Limited Edition, with 2.0 TFSI engine upgraded to 228 kW (310 PS; 306 bhp) of maximum power and 425 N⋅m (313 lbf⋅ft).

In the interior, there is a driver-oriented centre console hosting a 5.8-inch touch-screen infotainment display with some models featuring a proximity sensor, also used in the Volkswagen Golf, as well as ambient lighting.

The full-LED headlamps offer numerous advantages over standard halogen bulbs such as improved illumination, a close to daylight colour temperature, lower energy consumption and an extended service life.

[46] In January 2017, the León received a subtle facelift which included a reshaped front bumper with a grille that has been stretched by 40mm and features restyled LED headlights.

Interior changes included an electric parking brake with Hill Hold Control (HHC) as standard, a larger eight-inch touchscreen infotainment system with Apple CarPlay, Android Auto and MirrorLink.

[50][51] The Sub8 Performance pack was launched in August 2014 for the Cupra 280, it featured side skirts, lightweight 19-inch alloy wheels and 30 mm larger ventilated brake discs with Brembo calipers.

[52][53] The Ultimate Sub8 pack was launched in February 2015 for the Cupra 280, which included several weight-saving measures including: removing the León's centre armrest, standard climate control system is replaced with a smaller heater, reducing the number of speakers from eight to four, removing the centre console armrest, front storage units, and rear air vents.

Changes to the revised model included the addition of a gasoline particulate filter (GPF), and as the name suggests, gave the 2WD hatchback a 290 PS (213 kW) power output.

[61][62] In 2012, the SEAT León Mk3 was tested for its safety performance under the Euro NCAP assessment scheme and it achieved a 5-star overall rating:[63] In 2013, the Spanish-made SEAT León Mk3 in its most basic Latin American market configuration was tested for its safety performance under the Latin NCAP assessment scheme and it achieved 5 stars for adult occupants and 4 stars for toddlers:[64] In 2015, the Spanish-made SEAT León ST in its most basic Latin American market configuration was tested for its safety performance under the Latin NCAP assessment scheme and it achieved 5 stars for adult occupants and 5 stars for toddlers:[65] The SEAT León CONNECT is a special edition model that was released in 2015.

Based on the León ST Cupra 300, the Carbon Edition is fitted with the same 296 bhp 2.0-litre four-cylinder petrol engine mated to a six-speed DSG gearbox and Haldex all-wheel-drive system.

Only available in Monsoon Grey paintwork, while other new exterior touches include carbon front and rear diffusers, fibre side blades, and Cupra R 19-inch black and bright silver alloy wheels.

The ABT upgrade includes a copper body kit, 19-inch alloy wheels, Brembo brakes, and quad exhausts; the front splitter and rear diffuser, side skirts, and roof-mounted spoiler are all finished in carbon fibre.

The system allows the León to coast with the engine switched off during some driving scenarios and recover energy under braking which is then stored in a 48V lithium-ion battery.

[76] Standard equipment include: "KESSY" automatic locking and starting system, electronic parking brake, an eight-inch infotainment system, two USB ports, LED headlights with automatic high beam, electric and heated side mirrors, cloth upholstery, leather steering wheel and gear stick, and SEAT Connect.

[77] Standard equipment include: Blind Spot Detection, Exit Assist (alerts driver to any approaching vehicles visually and acoustically; stopping the car if necessary), Collision Assist (if an imminent collision is detected, sensors prepare the vehicle and its occupants by pre-tensioning seat belts and closing windows), Emergency Assist (if the driver seems inactive behind the wheel, it will activate the hazard lights, keep the car in its lane and then will apply the brakes until the car is brought to a gentle stop) and Predictive Adaptive Cruise Control.

[82] Optional features (some of which are standard on higher models) include Rear View Camera, BeatsAudio 9-speaker sound system, Park Assist, leather sport seats, and LED exterior lighting with automatic headlight adjustment.

[83] The 'Convenience Pack' includes Rain and auto-dimming light sensor with Coming and Leaving Home, windshield wiper intermittent control and breakaway interior rearview mirror.

[84] The Cupra León (PHEV) e-Hybrid's powertrain comprises a 148 bhp turbocharged 1.4-litre four-cylinder petrol engine, a 113 horsepower electric motor, and a 13 kWh lithium battery pack.

Available in two versions: The entry-level VZ2 variant features 19-inch alloy wheels, black brake calipers, a quad exhaust system, and copper-coloured exterior detailing.

During 2005, SEAT introduced the second generation León into the World Touring Car Championship (WTCC) to replace the Toledo Cupra which it had raced in the early rounds of the title.

The car featured several modifications, including a racing engine that developed over 191 kW (260 PS; 256 bhp), a Hewland sequential-shift gearbox (unrelated to the DSG), and an aerodynamic package for increased downforce (with its hatchback shape, the León was disadvantaged against conventional three-box saloons).

León TDI was also fielded by SEAT UK in the British Touring Car Championship with Jason Plato being the lead driver.

In 2009, Gabriele Tarquini became the Drivers' Champion with the León TDI, and SEAT won the Manufacturers' title for a second consecutive year.

In 2016 SEAT Sport introduced a TCR-spec version of the León with the original Cup Racer still being eligible in the International Series as well as national and regional championship utilising the TCR regulations.