Mid-Ohio Sports Car Course is a road course auto racing facility located in Troy Township, just outside the village of Lexington. It hosts a number of racing series such as Indycar, IMSA WeatherTech Sportscar Championship, and the NASCAR Xfinity Series, along with other club events such has SCCA and National Auto Sport Association.

The track was opened in 1962 by Les Griebling and several Mansfield-area businessmen as a location for weekend sports car racing. The track originally had 16 turns, with a left turn in what is today known as "thunder valley," but the turn was straightened after just one year of operation due to complaints of the track being too slow. The track hosted Can-am and F5000 through the 1970s and in 1980, it would host its first CART race with Johnny Rutherford taking victory with Chaparral.

In 1982 Mid-Ohio was purchased by Jim Trueman, a renowned road racer and the founder of Red Roof Inns. Trueman added permanent grandstands, amphitheater-style seating, garages with spectator balconies, a five-story media and hospitality center, tunnels and an updated paddock area. In addition, a tall, three-sided scoreboard tower was constructed in the infield, strategically placed such that it was visible from nearly all spectator areas around the track. In 1986 Trueman had passed away from cancer, making his wife and daughter taking over management for the facility. In 1989 Truman's daughter, Michelle Trueman, was named the president of the circuit in 1989 and saw day-to-day operations of the track.

In 1990 the track underwent a refurbishment. A new retaining wall was built, the entire track was resurfaced, widened, and concrete was paved in the apexes of the turns to prevent asphalt deterioration. In addition, a straightaway was paved through the chicane, allowing for two different track layouts, the original 2.4-mile (3.9 km) circuit and a new 13-turn, 2.258 mile (3.634 km) circuit.

In 2006 the track again underwent extensive renovation. The track and pit lane were completely resurfaced and connectors were added to the track's famed Keyhole section to allow for three separate road course configurations. Also completed was the removal of concrete patches from the track, the relocation of the wall and guardrail at Turn 1, the expansion of gravel traps at the exits of Turn 1 and the keyhole, the replacement of all remaining old-style catch fencing and the standardization of curbing throughout the circuit. These changes have resulted in a faster, safer, more competitive and attractive facility for drivers, riders and race fans. A new motorcycle "short course" was created by connecting turn one with the backstretch and another motorcycle oval was created by connecting the chicane straight with the backstretch. The additional layouts allow simultaneous use of the multiple course, for instructional and competitive uses. The improvements also included a motocross facility, that has since been used for the AMA Vintage Motorcycle days event.

In 2019 the ARX came to the track which was the first time rallycross had come to the circuit. The course was a 10-turn, 0.7 mile (1.13 km) and utilized the keyhole section of the track.

On March 2, 2011 it was announced that the track had been purchased from Truesports by Green Savoree Racing Promotions, which also promotes other IndyCar races, ending Truesports' 29 years of ownership.

There is grandstand seating for 12,000 spectators and three observation mounds alongside the track raise the capacity to over 75,000. Mid-Ohio is classified as an FIA Grade Two circuit.