Ray Charles Leonard, better known as Sugar Ray Leonard, is an American former professional boxer. Often regarded as one of the greatest boxers of all time, he competed professionally between 1977 and 1997, winning world titles in five weight classes; the lineal championship in three weight classes; as well as the undisputed welterweight championship. Leonard was part of the "Four Kings", a group of boxers who all fought each other throughout the 1980s, consisting of Leonard, Roberto Durán, Thomas Hearns, and Marvin Hagler. Leonard was the only one of them to beat the other three. As an amateur, Leonard won a light welterweight gold medal at the 1976 Summer Olympics.
The "Four Kings" created a wave of popularity in the lower weight classes that kept boxing relevant in the post-Muhammad Ali era, during which Leonard defeated future fellow International Boxing Hall of Fame inductees Hearns, Durán, Hagler, and Wilfred Benítez. Leonard was also the first boxer to earn more than $100 million in purses, and was named "Boxer of the Decade" in the 1980s.