Floyd Joy Mayweather, Jr. (born Floyd Sinclair on February 24, 1977), is an American professional boxer. He is a five-division world champion, where he won nine world titles in five different boxing weight classes. He is undefeated as a professional boxer, with 41 wins including 25 by way of knockout. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.