2006 IndyCar Series

The 2006 IRL IndyCar Series was the 95th season of premier American open-wheel car racing and the 11th season of the IndyCar Series as sanctioned by the Indy Racing League (IRL), running alongside the rivaling 2006 Champ Car World Series. The season featured 14 rounds between March 26 and September 10. Sam Hornish Jr. of Marlboro Team Penske won the series' premier event, the 90th Indianapolis 500, and the Drivers' Championship.

Dan Wheldon entered the season as the defending Drivers' Champion and Indianapolis 500 winner. In the off-season, Wheldon left Andretti Green Racing, the team with which he won the title in 2005, to drive for Target Chip Ganassi Racing. The season began under slight tumultuousness as three tracks (Phoenix Raceway, Auto Club Speedway, and Pikes Peak International Raceway) were taken off the schedule and Chevrolet and Toyota withdrew from IndyCar, leaving Honda as the sole engine provider. To make matters worse, rookie driver Paul Dana was killed in a crash during a warm-up session for the opening round at Homestead–Miami Speedway.

Throughout the 2006 season, Hornish Jr. faced stiff competition from teammate Hélio Castroneves and Target Chip Ganassi Racing drivers Wheldon and Scott Dixon. The four drivers' battle persisted into the season finale, the Peak Antifreeze Indy 300, which ended with Hornish Jr. and Wheldon tied for the championship. Hornish Jr. was awarded the championship on account of earning more wins in the season than Wheldon.