The 1981 NASCAR Winston Cup Series was the thirty-third season of professional stock car racing in the United States and the 10th modern-era Cup Season. It was the first year of the Gen 3 car. Because of the energy crisis, manufacturers were downsizing their cars to be more fuel-efficient, which NASCAR reflected by mandating a 110-inch wheelbase that still exists today. The season began at Riverside International Raceway with the first Winston Western 500 on January 11, 1981 and ended with the same event on November 22. Darrell Waltrip won his first championship with point margin of fifty-three points over Bobby Allison. Ron Bouchard was named Rookie of the Year.

Teams and drivers

Season schedule and recap

Season summary

Race reports

Final point standings

(key) Bold – Pole position awarded by time. Italics – Pole position set by owner's points.

• – Most laps led. Source: