The 2004 IRL IndyCar Series was the ninth season of the IRL IndyCar Series, a motor racing championship for top-level American open-wheel cars that was sanctioned by the Indy Racing League (IRL). It represented the 93rd official championship season of American open-wheel car racing along with the rivaling 2004 Champ Car World Series. The season featured 16 races, beginning at Homestead on February 29 and ending at Texas on October 17. It was the last season of the series that solely featured oval tracks before road courses and street circuits were added beginning in the 2005 season.