James "Buster" Douglas is an American former professional boxer who competed between 1981 and 1999. He reigned as undisputed world heavyweight champion in 1990 after defeating Mike Tyson to win the title. His victory over Tyson is regarded as one of the greatest upsets in sports history.

Douglas was a 42-to-1 underdog going into his 1990 fight against Tyson, who was undefeated and considered to be the best boxer in the world for his domination of the division over the previous three years. Defying expectations, Douglas knocked out Tyson in the 10th round to claim the WBC, WBA, and IBF titles. He reigned as the world heavyweight champion for eight months until he was defeated by Evander Holyfield in his only title defense. Retiring shortly after the fight, Douglas engaged in a series of comeback fights between 1996 and 1999 before retiring a second and final time.