The 2005 Rolex Sports Car Series season was the sixth season of the Rolex Sports Car Series run by the Grand American Road Racing Association. The format was reduced to two classes, Daytona Prototypes (DP) and Grand Touring (GT). 14 races were run from February 5, 2005 to November 5, 2005. Laguna-Seca and Hermanos Rodríguez were added. It set the record for the longest Rolex season.