The 2011 NASCAR Sprint Cup Series was the 63rd season of professional in the United States and the 40th modern-era Cup series season. The season included 36 races and two exhibition races, beginning with the Daytona 500 at Daytona International Speedway and ending with the Ford 400 at Homestead-Miami Speedway. The final ten races were known as 2011 Chase for the Sprint Cup.
During the 2010 season, NASCAR announced several calendar changes, including race additions at Kansas Speedway and Kentucky Speedway, and the removal of one race each from Atlanta Motor Speedway and Auto Club Speedway. Once the 2010 season had concluded, NASCAR also announced changes to the point system, and that the fuel changed from Sunoco unleaded to an ethanol blend called 'Sunoco Green E15'.
Stewart Haas racing won the Owners' Championship, while Tony Stewart, co-owner of Stewart-Haas Racing with Gene and Margaret, won the Drivers' Championship with a victory at the final race of the season in a tiebreak over Carl Edwards. Chevrolet won the Manufacturers' Championship with 248 points.
The preseason testing season began on January 20, 2011, with a three-day test at the Daytona International Speedway to test the new nose on the car, as well as the new surface. Also in the sessions, the opening of the restrictor plate was reduced from the 30/32 inch plate used in tire testing in December to 29/32 inch. NASCAR vice president for competition Robin Pemberton stated, "We'll have to get back and talk to the teams and look at the speeds from the last two days of testing. I think we have some high-water marks at 197-and-a-half which, depending on where they pulled up in the draft, it may be a little quick, but it's hard to say." During the first session on the morning of January 20, 2011, 33 drivers participated, and Clint Bowyer was quickest with a speed of 184.216 mph while David Reutimann had the highest speed of 195.780 mph during the second session in the afternoon.