Michael Fred Phelps is an American swimmer who has, overall, won 16 Olympic medals—six gold and two bronze at Athens in 2004, and eight gold at Beijing in 2008, becoming the most successful athlete at both of these Olympic Games editions. In doing so he has twice equaled the record eight medals of any type at a single Olympics achieved by Soviet gymnast Alexander Dityatin at the 1980 Moscow Summer Games. His five golds in individual events tied the single Games record set by compatriot Eric Heiden in the 1980 Winter Olympics and equaled by Vitaly Scherbo at the 1992 Summer Games. Phelps holds the record for the most gold medals won in a single Olympics; his eight at the 2008 Beijing Games surpassed American swimmer Mark Spitz's seven-gold performance at Munich in 1972. Phelps' Olympic medal total is second only to the 18 Soviet gymnast Larisa Latynina won over three Olympics, including nine gold. Furthermore, he holds the all-time record for most gold Olympic medals, at 14.

Phelps's international titles and record breaking performances have earned him the World Swimmer of the Year Award six times and American Swimmer of the Year Award eight times. He has won a total of sixty-six medals in major international competition, fifty-four gold, nine silver, and three bronze spanning the Olympics, the World, and the Pan Pacific Championships. His unprecedented Olympic success in 2008 earned Phelps Sports Illustrated magazine's Sportsman of the Year award.

After the 2008 Summer Olympics, Phelps started the Michael Phelps Foundation, which focuses on growing the sport of swimming and promoting healthier lifestyles. As a participant in the US Anti-Doping Agency's "Project Believe" program, Phelps is regularly tested to ensure that his system is clean of performance-enhancing drugs.

2009 World Championship

At the 2009 National Championships, Phelps drastically shortened his program, only swimming in three individual events. In his first event, the 200 m freestyle, Phelps won with a time of 1:44.23.In his second event, the 200 m butterfly, Phelps easily won with a time of 1:52.76, 0.88 seconds ahead of the second place finisher.In his third event, the 100 m butterfly, Phelps won with a world record time of 50.22.Phelps (center) before the start of the 200 m butterfly semifinal during 2009 FINA World Championships.

At the 2009 World Aquatics Championships, Phelps won a total of 6 medals, 5 golds and 1 silver. In his first event, the 4×100 m freestyle relay, Phelps swam the lead-off leg in 47.78, well off his 47.51 performance in Beijing but the American team was able to edge out Russia and France for the gold.For his second race, the 200 m freestyle, Phelps lost his first race in four years to Germany's Paul Biedermann. Phelps touched second in 1:43.22 but Biedermann smashed Phelps' record of 1:42.96 set in Beijing a year ago with a time of 1:42.00.Phelps took the silver graciously, but coach Bob Bowman threatened to withdraw Phelps from international competition because Bowman claimed Biedermann had an unfair advantage because he was wearing a full polyurethane swim suit, specifically an Arena X-Glide. Bowman said, "It took me five years to get Michael from 1:46 to 1:42 and this guy has done it in 11 months. That's an amazing training performance. I'd like to know how to do that." Phelps rebounded from this loss and for his third race, the 200 m butterfly, Phelps won the gold and broke his own world record of 1:52.03 with a time of 1:51.51.For his fourth race, the 4×200 m freestyle relay, Phelps swam the lead-off leg in 1:44.49 as the team went on to win the gold medal and break the world record set last year.After his loss in the 200 m freestyle, many thought Phelps was vulnerable coming into the final for the 100 m butterfly.His closest competitor, Milorad Čavić, who wore an Arena X-Glide (the same suit Biedermann beat Phelps with), thought people were making excuses for Phelps because he was wearing an LZR Racer. Čavić even offered to buy Phelps a new suit.For his fifth race, the 100 m butterfly, Phelps won the gold and became the first man under 50 seconds, beating Čavić 49.82 to 49.95.The victory prompted a fierce celebration from Phelps, who sat on the lane rope, and pumped his chest and swimsuit.For his final event, the 4×100 m medley relay, Phelps won his fifth gold medal. Phelps, along with teammates Aaron Peirsol, Eric Shanteau, and David Walters, set a new world record in the event with a time of 3 minutes and 27.28 seconds.