He gained fame in 1974 by sponsoring the boxing match between Muhammad Ali and George Foreman in Zaire, popularly known as "The Rumble in The Jungle". He consolidated his position as an influential promoter the next year by sponsoring a third match for Ali against Joe Frazier in Manila, the capital of the Philippines, which King named "The Thrilla in Manila".
In Cleveland, Ohio in 1954, King shot and killed a man attempting to rob one of his gambling houses; the death was ruled a "justifiable homicide". King served time for killing a man in 1966 who allegedly owed him money, whom he beat to death. Although convicted of second degree murder, the judge reduced the conviction to nonnegligent manslaughter. King has been investigated for possible connections with organized crime. During a 1992 Senate investigation King took the Fifth Amendment when questioned about his connection to mobster John Gotti. He has responded to these acts by calling them racist.
Apart from Ali, Frazier and Foreman, he has promoted such boxers as Evander Holyfield, Felix Trinidad, Mike Tyson, Larry Holmes, Carlos De Leon, Wilfredo Benitez, Wilfredo Gomez, Roberto Duran, Julio Cesar Chavez, Juan Laporte, Edwin Rosario, Salvador Sanchez, John Ruiz, Hector Camacho, Christy Martin, Aaron Pryor, Alexis Arguello and many others.
In May of 2003, King was sued by Lennox Lewis, who wants 385 million dollars from the promoter, claiming King used threats to pull Tyson away from a rematch with Lewis. This is one of several lawsuits King has gone through.
Don King is well-known for his eccentric behavior and outlandish style. He has a rather unusual hairstlye, and is fond of wearing loud, brightly colored clothing and lots of jewelry. He is also a very grandiose public speaker.