The first world record in the 100 metres butterfly in long course (50 metres) swimming was recognised by the International Swimming Federation (FINA) in 1957, for both men and women. In the short-course (25 metres) swimming events, the world's governing body recognizes world records since March 3, 1991.
Michael Fred Phelps II (born June 30, 1985) is an American former competitive swimmer. He won more Olympic medals than any other athlete, a total of 28 medals across four Olympic Games. Phelps also holds the all-time records for Olympic gold medals (23), Olympic gold medals in individual events (13), and Olympic medals in individual events (16). At the 2004 Summer Olympics in Athens, Phelps tied the record of eight medals of any color at a single Games, held by gymnast Alexander Dityatin, by winning six gold and two bronze medals. Four years later, when he won eight gold medals at the 2008 Beijing Games, he broke fellow American swimmer Mark Spitz's 1972 record of seven first-place finishes at any single Olympic Games. At the 2012 Summer Olympics in London, Phelps won four gold and two silver medals, and at the 2016 Summer Olympics in Rio de Janeiro, he won five gold medals and one silver. This made him the most successful athlete of the Games for the fourth Olympics in a row.
Phelps is a former long course world record holder in the 200-meter freestyle, 100-meter butterfly, 200-meter butterfly, 200-meter individual medley, and 400-meter individual medley. He has won 82 medals in major international long course competitions, of which 65 were gold, 14 silver, and three bronze, spanning the Olympics, the World Championships, and the Pan Pacific Championships. Phelps's international titles and record-breaking performances have earned him the World Swimmer of the Year Award eight times and American Swimmer of the Year Award eleven times, as well as the FINA Swimmer of the Year Award in 2012 and 2016. Phelps earned Sports Illustrated magazine's Sportsman of the Year award due to his unprecedented Olympic success in the 2008 Games.
Milorad "Milo" Čavić (Serbian Cyrillic: Милорад "Мило" Чавић, Serbian pronunciation: [mîloraːd tʃǎːʋitɕ]; born May 31, 1984) is a Serbian former professional swimmer. He won a silver medal in the 100-meter butterfly at the 2008 Summer Olympics in a historic race with American swimmer Michael Phelps. Čavić also was World and European champion, as well as world record holder. He is one of five swimmers to break 50 seconds in the 100m butterfly.
The world records in swimming are ratified by World Aquatics (formerly known as FINA), the international governing body of swimming. Records can be set in long course (50 metres) or short course (25 metres) swimming pools. World Aquatics recognizes world records in the following events for both men and women, except for the mixed relays, where teams consist of two men and two women, in any order.
The ratification process is described in FINA Rule SW12, and involves submission of paperwork certifying the accuracy of the timing system and the length of the pool, satisfaction of FINA rules regarding swimwear and a negative doping test by the swimmer(s) involved. Records can be set at intermediate distances in an individual race and for the first leg of a relay race. Records which have not yet been fully ratified are marked with a '#' symbol in these lists.