A quadruple champion, also known as a grand slam champion, occurs in different sports when a competitor wins four crowns, titles, medals, belts or another distinction. The definition varies depending on the sport.

In boxing, a quadruple champion is a boxer who has won world titles in four different weight classes.

The first ever man to earn that enormous distinction was Thomas Hearns on October 29, 1987. Hearns won his first four titles at the following divisions: welterweight (147 lbs), light middleweight (154 lbs), middleweight (160 lbs) and light heavyweight (175 lbs). By later winning a super middleweight title, he also became the first to win world titles in five weight divisions.

The second man was Sugar Ray Leonard, who on November 7, 1988, won his first championships at welterweight (147 lbs), light middleweight (154 lbs), middleweight (160 lbs), super middleweight (168 lbs) and light heavyweight (175 lbs). There are five titles in five divisions but his case is extremely rare: Leonard fought for two different belts in two different weight divisions the same night: Super middleweight (168 lbs) and light heavyweight (175 lbs) against Donny Lalonde so any of the titles can be attached as his fourth title.

Leo Gámez was the first boxer to win titles in four of the lightest divisions from mini flyweight (105 lbs), light flyweight (108 lbs), flyweight (112 lbs) to super flyweight (115 lbs), having accomplished the feat on October 9, 2000.

Alain Prost, Max Verstappen, Lewis Hamilton and Sebastian Vettel won four F1 world championships.

Juha Kankkunen and Tommi Mäkinen both won four World Rally Championships.

Yvan Muller is the only person to win four World Touring Car Championships.