Michael Phelps
The most decorated Olympian in history across all sports. Phelps won 28 Olympic medals, 23 of them gold, over five Games from Sydney 2000 to Rio 2016, including a still-unmatched eight golds at Beijing 2008 that broke Mark Spitz's 1972 record of seven. He set 39 world records and claimed 26 world-championship titles. His range was staggering: Olympic gold in the 100m and 200m butterfly, the 200m and 400m individual medley, the 200m freestyle and a stack of relays. Coached by Bob Bowman, Phelps combined a huge wingspan, relentless training volume and famous racing nerve, touching out Milorad Cavic by 0.01 seconds in Beijing. No swimmer has matched his blend of longevity, versatility and championship hardware, and none is close on career gold medals.