The race was conceived by Jules de Their and Henri Langlois Van Ophem just one year after the inaugural 24 Hours of Le Mans was run. It debuted in 1924 over a 15-kilometre circuit using public roads between the towns of Francorchamps, Malmedy and Stavelot, under the auspices of the Royal Automobile Club of Belgium. This original road course gave the event an elemental character that persisted through its early decades, as cars of wildly varying power and provenance contested the Belgian countryside.
The present 7.004-kilometre permanent circuit was inaugurated in 1979, with only slight variations since then. Spa-Francorchamps had already earned a fearsome reputation from Formula 1 and sports car racing, and the enclosed circuit retained the essence of the old layout, including the famous Eau Rouge and Raidillon corners that would become defining features of the venue.
The Spa 24 Hours held status within several major international championships across its long history. It formed part of the European Touring Car Championship from 1966 to 1973, again in 1976, and from 1982 to 1988, with the exception of 1987 when it counted towards the inaugural World Touring Car Championship. The event also counted towards the World Sportscar Championship in 1953 and the World Endurance Championship in 1981.
The race attracted a remarkable variety of machinery during the touring car era. Cars entered ranged from the Russian Moskvitch and models with sub-1-litre engines such as the NSU Prinz TT to the V8-powered Mercedes-Benz 300 SEL 6.3. That large Mercedes, tuned by Mercedes-AMG and displacing 6,834 cc with 420 horsepower, finished as high as second place in 1971, earning the nickname the "Red Pig" for its ungainly performance.
The 1975 race was marked by fatal incidents. Dutch driver Wim Boshuis was killed when his vehicle collided with other cars on the track, and a track marshal was killed 30 minutes later when Belgian driver Alain Peltier collided with a railing. These events prompted wider reflection on circuit safety standards during a period when motorsport was confronting its inherent dangers.
The 2004 race delivered a historic milestone when Swiss driver Lilian Bryner was part of the victorious team aboard a Ferrari 550 entered by BMS Scuderia Italia. It was the first time in history that a female driver had been part of the winning team of a 24-hour endurance race in a Gran Turismo car with more than 500 horsepower.
The contemporary Spa 24 Hours operates as a centrepiece event of the GT World Challenge Europe Powered by AWS and the Intercontinental GT Challenge. It was previously a round of the FIA GT Championship, featuring GT1 and GT2 machinery. Cars now compete in FIA GT3 and GT3 Cup classifications, reflecting the broader shift in international GT racing toward the GT3 technical regulations that standardised the category from the mid-2000s onwards.
The race became part of SRO Group's Intercontinental GT Challenge from its inaugural 2016 season, linking Spa with events at Bathurst and elsewhere to form a global endurance calendar. The 2020 edition was held behind closed doors for the first time due to the COVID-19 pandemic.
In September 2022, a scheduling conflict arose when the 2023 Belgian Grand Prix was set for July 28 to 30, clashing with the Spa 24 Hours' traditional midsummer date. The endurance race was rescheduled to early July to avoid the conflict.
A distinctive feature of the Spa 24 Hours is the Coupe du Roi, or King's Cup, awarded to the best manufacturer. Crucially, the Coupe du Roi winner is not necessarily the outright race winner; it is determined by the manufacturer with the most points accumulated across all its entered cars. Australian manufacturer Holden famously won the Coupe du Roi in 1986 despite their cars finishing the race in 18th, 22nd and 23rd positions outright, illustrating how the award rewards depth of entry rather than a single car's performance.
The longevity of the Spa 24 Hours reflects the enduring appeal of the Circuit de Spa-Francorchamps as a venue and the format of endurance racing more broadly. As one of the only 24-hour races outside of Le Mans to have run continuously since the early years of motor racing, the event occupies a unique position in the calendar. Its transition from touring cars to GT machinery mirrored the evolution of the broader sport, yet the race retained its identity through the permanence of the circuit and the challenge that Spa imposes on drivers and machinery across a full day and night.