The Riley & Scott Mark III was a sports prototype auto racing car developed by Bob Riley, Bill Riley and Mark Scott of Riley & Scott Cars Inc. Initially designed in 1993, the car was created for the World Sports Car (WSC) category which was to debut in the North American IMSA GT Championship during their 1994 season. It was not until 1995 that the first Mk III was completed, but the construction of further cars allowed a variety of teams to campaign in several North American and European racing series, including competing at the 24 Hours of Le Mans.

A Le Mans Prototype (LMP) is a type of sports prototype race car used in various races and championships, including the 24 Hours of Le Mans, FIA World Endurance Championship, IMSA SportsCar Championship, European Le Mans Series and Asian Le Mans Series. Le Mans Prototypes were created by the Automobile Club de l'Ouest (ACO). The technical requirements for an LMP include bodywork covering all mechanical elements of the car. As of 2023, there are two classes within Le Mans Prototypes, designated LMP2 and LMP3.