The 1973 NASCAR Winston Cup Series was the 25th season of professional in the United States and the 2nd modern-era Cup season. The season began on Sunday January 21 and ended on Sunday October 21. 31 races were scheduled in the 1973 season. 28 were held.
Benny Parsons was crowned Winston Cup champion at the end of the season finishing 67 points ahead of Cale Yarborough. Lennie Pond was named NASCAR Rookie of the Year, succeeding Larry Smith, who was fatally injured in the year's Talladega 500. David Pearson dominated the season winning 11 of the 18 races he entered. Ten of Pearson's wins were on superspeedways, setting a NASCAR record for superspeedway wins that lasted until Bill Elliott broke it in 1985.
Rule changes made in late November 1972 adjusted maximum carburetor sleeve sizes depending upon the type of engine and manufacturer of a given car. As NASCAR President Bill France, Jr. explained, the goal of the adjustments was to differentiate between engines manufactured specifically for racing, and "volume production" engines that came off a consumer assembly line. This was done "...so the events next year can continue to be representative of the type of the extremely close competition that has been typical of NASCAR racing."
In 1973, the NASCAR points system was changed. In 1972, only the number of laps completed in a race (regardless of position) counted toward the calculation of points. In 1973, points were awarded both for the number of laps in a race completed, and for a finish in the top 50 in a race, a higher placing receiving more points. Additionally, the first-place finisher received a 25-point bonus.
Bobby Allison left Richard Howard's racing team, and would drive his own Chevrolet in 1973. Bobby Allison's team would also furnish a car for his brother, Donnie Allison. Taking his place on the Howard racing team would be Cale Yarborough, returning from the division.