The 2021 Stadium Super Trucks Series was the ninth season of the Stadium Super Trucks. The season began with the Grand Prix of St. Petersburg on April 24–25 and ended at the Grand Prix of Long Beach on September 24–26.
Matthew Brabham finished on the podium in each of the ten races and won twice to claim his third consecutive championship. This broke a three-way tie with Robby Gordon and Sheldon Creed for the most titles, and the former finished second in points.