The circuit combines purpose-built, race-specific sections with public roads that remain open for ordinary traffic during most of the year. These public roads are used exclusively as racing venue during the 24 Hours of Le Mans itself. The current layout, designated Circuit N°15, has been in use since 2018. Prototype cars circulate at average lap speeds in excess of 240 km/h (150 mph), and the permanent capacity of the shorter Bugatti Circuit infield is 100,000 spectators. The Musee des 24 Heures du Mans, a motorsport museum dedicated to the race, is located at the main entrance to the venue.
The original layout was a triangle running from Le Mans south to Mulsanne, northwest to Arnage, and back north to Le Mans, measuring 17.261 km (10.725 mi) and unpaved. A bypass shortened the route in 1929; the city was bypassed entirely in 1932 with the addition of the section from the pits via the Dunlop Bridge and the Esses to Tertre Rouge, producing the classic 13.492 km (8.384 mi) configuration that remained largely unchanged for decades. The pit straight of this classic era was extremely narrow — approximately 3.7 m (12 ft) wide — and formed part of the public road itself with no separation from the pits.
Car speeds rose sharply through the 1960s. A Ford chicane was added before the pits for the 1968 race, and Armco barriers were fitted for 1969. The harrowing Maison Blanche kink claimed many cars over the years, including three Ferrari 512 variants and several drivers' lives, among them John Woolfe in 1969. The year 1971 was the last in which the classic unmodified layout was used, with prototypes averaging over 240 km/h. In 1972 the track was substantially rebuilt at a cost of 300 million francs, adding the Porsche Curves to bypass Maison Blanche and reconfiguring the pit area and straights.
Further changes came in 1979, when new public road construction required the Tertre Rouge profile to be reworked into a faster double-apex corner. In 1986 a new roundabout at Mulsanne corner necessitated an additional track section. A chicane was added to the fast Dunlop curve in 1987. In 2002 and 2006, the run through the Esses and Dunlop Chicane area was progressively reconfigured, and after the fatal crash of Danish driver Allan Simonsen at the 2013 race, Tertre Rouge was re-profiled again for safety.
The most celebrated feature of the circuit has long been the Ligne Droite des Hunaudières — the Mulsanne Straight — a roughly 6 km (3.7 mi) section of Route Departementale D338 leading to the village of Mulsanne. Cars spent nearly half the lap at full throttle on this stretch. The Porsche 917 long tail reached 362 km/h (225 mph) in 1969–71; Group C prototypes of the late 1980s pushed beyond 400 km/h. The absolute record was set at the 1988 24 Hours of Le Mans by Roger Dorchy, driving the WM Peugeot "Project 400" entry built with exceptional straight-line aerodynamics. Dorchy was clocked at 407 km/h (253 mph) down the straight — though Peugeot's concurrent launch of the 405 road car led to the figure being widely (and incorrectly) remembered as 405 km/h.
Fatal accidents involving Jean-Louis Lafosse in 1981 and Jo Gartner in 1986, combined with escalating tyre and engine failures caused by sustained maximum speed, led the FIA to decree that no circuit it sanctioned could contain a straight longer than 2 km. Accordingly, two chicanes were inserted on the Mulsanne Straight before the 1990 race. The fastest qualifying lap average speed fell only modestly — from 249.826 km/h to 243.329 km/h by 1992 — underscoring how much lap time the rest of the circuit contributes.
Located within the larger venue is the Bugatti Circuit, a 4.185 km (2.600 mi) permanent track built in 1965 and named after Ettore Bugatti. It shares the pit lane complex, the Ford Chicane at the end of the lap, and the Dunlop straight with the full Le Mans circuit; at the key junction vehicles turning left proceed toward the 24-hour course while those turning right at La Chapelle continue on the Bugatti layout. The dedicated infield section includes Garage Vert, a back straight, the S du Garage Bleu, and Raccordement, rejoining at the Ford Chicane.
The Bugatti Circuit hosted the 1967 French Formula One Grand Prix — the only World Championship round ever held at Le Mans — and has since been the permanent home of the French motorcycle Grand Prix round of the MotoGP championship. It also hosts the 24 Heures Motos endurance motorcycle race, the European Truck Racing Championship 24 Heures Camions, and a variety of national series. The track was home base for Pescarolo Sport, founded by legendary French sportscar driver Henri Pescarolo.
The venue hosts a dense annual calendar across multiple disciplines. The 24 Hours of Le Mans remains the centrepiece, supported by the Le Mans Cup and associated FIA World Endurance Championship weekend events each June. The French motorcycle Grand Prix takes place in May, and the 24 Heures Motos endurance race occupies a spring weekend. The European Truck Racing Championship holds its 24 Heures Camions round in September, and the Le Mans Classic historic festival uses the circuit in July.