Muhammad Ali was ranked Sports Personality of the Century by BBC in 2000.
Muhammad Ali ( [ ɑːˈliː ] born Cassius Marcellus Clay Jr. ; January 17 , 1942 -- June 3 , 2016 ) was an American professional boxer and activist . He was ranked as the greatest athlete of the 20th century by Sports Illustrated , the Sports Personality of the Century by the BBC , and the third greatest athlete of the 20th century by ESPN SportsCentury .