Burton won two Olympic gold medals in freestyle swimming in Mexico City in 1968, in the 400 and 1,500 metres.
When he then defended his gold in the longer distance in Munich four years later, he made history as the first American swimmer to win two straight gold medals in the 1,500-metre freestyle.
However, he was overshadowed by his compatriot Mark Spitz, who won an unlikely seven Olympic gold medals during the 1972 Games.
Mike Burton died of complications from Alzheimer's disease, his son Eric wrote on Facebook.
