Won the cruiserweight world title a record four times and compiled a career record of 52-8-1 with notable wins over Leon Spinks and Bernard Benton.
He was born in Trujillo Alto and made his professional debut in March 1974.
He lost his WBC title in a shocking upset to S. T. Gordon, who knocked him out in the second round.
He began focusing on furthering the boxing career of his son, Carlos de León Jr., after his own retirement.
He and Sugar Ray Robinson are two of the only fighters in history to have won one division's world championship at least three times.