Tris Dixon, editor of Boxing News, said Ali, who was born Cassius Clay in Kentucky, has a list of accomplishments in the ring that most athletes can only dream of, CNN reported Wednesday.
"Everything that Ali has done and stood for, you can only aspire to be like him," Dixon said. "He was the king in the biggest and best era of heavyweight champions."
Ali, who rose to prominence with a gold medal in the 1960 Olympic Games in Rome, retired from boxing in 1981 and was diagnosed with Parkinson's disease in 1994.
"There will never be anyone like Ali," Dixon said. "There will be people like Tiger Woods and Michael Jordan who reflect their times, but there will never be someone who means as much to the world and the cultural landscape as much as Ali did."