The circuit was conceived in 1920 by Jules de Thier, owner of the Liège newspaper La Meuse, who with local officials identified the roads connecting Francorchamps, Malmedy, and Stavelot as a natural racing triangle. The inaugural car race was held in 1922. Two years later, in 1924, the first 24 Hours of Francorchamps touring car race ran on the circuit. Grand Prix racing arrived in 1925, making Spa one of the earliest permanent locations for top-level single-seater competition.
The track's original 14.982 km length was gradually refined. In 1939 the slow uphill U-turn at the Ancienne Douane hairpin after Eau Rouge was bypassed with a sweeping run straight up the hill — the Raidillon — transforming one of the circuit's key transitions. After World War II further modifications at Malmedy and Stavelot produced the definitive pre-1979 layout of 14.100 km.
The old Spa circuit was, above all, a test of sustained nerve. Unlike circuits punctuated by slow corners and chicanes, almost every section of Spa demanded either flat-out commitment or the absolute limit of braking. The starting straight dropped toward the Eau Rouge creek before the Raidillon swept cars steeply uphill at unabated speed. From there, the Kemmel straight and the fast Burnenville curves carried cars at over 290 km/h before the descent toward the Masta Kink — described by Jackie Stewart as "by far the most difficult corner in the world." Masta was a left-right kink set between two straight sections each approximately 2.4 km long; drivers approached and departed it at close to 300 km/h. After Masta, La Carrière led through uphill bends before the high-speed Blanchimont left-hander and the La Source hairpin completed the lap. A full lap took approximately three to four minutes and the circuit had barely a metre of run-off anywhere.
Spa's beauty and savagery were inseparable. In the 1960s, ten drivers were killed in car races at the circuit. At the 1960 Belgian Grand Prix alone, Chris Bristow and Alan Stacey died within 15 minutes while Stirling Moss crashed heavily during practice. The 1969 Belgian Grand Prix was boycotted by Formula One drivers, who demanded safety modifications the circuit owners were unable to implement on short notice. Armco barriers were added in 1970, but even with temporary chicanes the average race speed still exceeded 240 km/h, and the 1971 race was cancelled entirely after the improvements still failed to meet mandatory standards. Formula One did not return until the modern circuit opened in 1983.
Multiple fatalities during the 24 Hours of Spa touring car races in 1973 and 1975 were the final confirmation that large-capacity racing machinery had outgrown the old circuit. By 1978 — the last year of the original layout — only the Belgian motorcycle Grand Prix and the Spa 24 Hours touring car race remained as events willing to run there.
Jackie Stewart, who won his most celebrated victory at Spa in the fog and rain of the 1968 German Grand Prix and who lost control of his BRM at the Masta Kink in 1966 — trapped upside-down with broken ribs while fuel soaked over him — was the most vocal critic of the circuit's safety standards and a driving force behind the eventual mandatory changes to Formula One venues in general. He described the old Spa circuit in 1986 as "ferocious as a tiger."
Masta was the circuit's defining hazard. Set in the middle of the two longest straights on the lap, it was a high-speed chicane through and past the scattered houses of the hamlet of Masta, where the track ran between walls and structures with no meaningful run-off. Cars had to decelerate from top speed for the kink and then re-accelerate immediately on the exit straight toward Stavelot. A mistake at Masta — a missed braking point, a car snapping sideways — left no recovery distance. Stewart's crash there in 1966 catalysed his lifelong campaign for driver safety in Formula One. Masta was not used after the 1970 season.
The fastest timed lap ever recorded on the full 14.100 km Spa circuit was a pole position lap of 3 minutes 12.7 seconds by Jacky Ickx in a Ferrari 312PB at the 1973 Spa 1000 km World Sportscar Championship race, representing an average speed of approximately 263 km/h. The fastest official race lap of the circuit was set by Henri Pescarolo in a Matra at the same event — 3 minutes 13.4 seconds, averaging 262 km/h.
Construction of the permanent replacement circuit began in 1978 and the new 6.947 km layout opened in 1979. It retained the start-finish area and the famous Raidillon de l'Eau Rouge combination, rejoining the old circuit at Blanchimont and adding a new final chicane before La Source. Formula One returned to Spa in 1983 and has raced there nearly every year since. The new circuit has itself been modified several times — most significantly in 2007 when the Bus Stop chicane was moved and La Source reprofiled, and again in 2022 when the runoff at Raidillon de l'Eau Rouge was substantially enlarged following renewed safety debate after a serious Formula 2 accident there in 2019 that killed Anthoine Hubert.
The classic Spa circuit represents a particular moment in the history of motor racing — the last era in which the fastest cars on earth competed on roads that were, in practical terms, unchanged from public use. Its legacy is its honesty: it did not hide risk behind infrastructure. For those who drove it and survived, it remained the reference point against which all other challenges were measured. In sim racing the old Spa layout has been recreated in historic racing titles, offering drivers an encounter with a course geometry that could not exist in any modern regulatory context.