The 2003 Rolex Sports Car Series season was the fourth season of the Rolex Sports Car Series run by the Grand American Road Racing Association. The season involved four classes, Daytona Prototypes (DP), Sports Racing Prototype II (SRPII), Grand Touring Sport (GTS), and Grand Touring (GT). 12 races were run from February 1, 2003 to November 2, 2003. Barber Motorsports Park was added.