The 2006 NASCAR Nextel Cup Series season, the 58th season of professional in the United States and the 35th modern-era NASCAR season, started at Daytona International Speedway on Sunday, February 12 with the Budweiser Shootout and ended on Monday, November 20, with the Ford 400 at Homestead-Miami Speedway. The Chase for the Nextel Cup began with the Sylvania 300 on Sunday, September 17, at New Hampshire International Speedway. Tony Stewart, driver of the No. 20 Chevrolet for Joe Gibbs Racing, was the defending series champion, but lost out in defending his championship this year, having finished outside of the top 10 in the points standings after the Chevy Rock and Roll 400. He did, however, claim a $1 million (US) bonus as the best finisher outside the Chase for the Nextel Cup drivers, winning three of the ten Chase races. By the end of the season Chevrolet had captured 23 victories, and 270 points to win the NASCAR Manufacturers' Championship over Ford.
The 2006 season was the first for Ford's all-new Fusion, which replaced the Taurus both in NASCAR and in showrooms. Also, a new version of the Chevrolet Monte Carlo, called the Monte Carlo Super Sport (SS for short) debuted on the circuit.