Ian James Thorpe (born October 13, 1982), Australian swimmer, is regarded as one of the greatest middle-distance swimmers of all time after winning the 200 and 400 metre freestyle races at the 2004 Olympics in Athens. He has won five Olympic gold medals, more than any other Australian.

Thorpe was born in Milperra, in the western suburbs of Sydney, and was educated at East Hills Boys High School. Although Thorpe's father, Ken, excelled as a cricketer, Ian did not have the same ability. Instead, he followed his sister, Christina, into competitive swimming. Thorpe made his first impact in 1997, when he was selected at 14 for the Australian team at the Pan Pacific competition in Fukuoka, Japan. He came second to another Australian teenager, Grant Hackett, in the 400 metre freestyle, beginning a rivalry which has continued ever since. He also excelled in the 200 metre freestyle and the 200 metre butterfly.

Since 1998 Thorpe has completely dominated the 400 metre freestyle event, winning the event at the 2000 Summer Olympic Games, the 2001 Fukuoka World Championships (at which he won a total of six gold medals), and again in Athens. His dominance has broadened to include the 200 and 400 metre freestyle (at which he holds the world record), and he is one of the fastest 100 metre freestylers in the world. He has been nicknamed "Thorpedo" by the Australian press for his swimming prowess.

Thorpe has also pushed Australian relay teams to unprecedented success, anchoring the winning 4x100 and 4x200 freestyle relay teams in Sydney, the first time the United States had ever been beaten in the events. In total, he has broken world records (either individually or as part of a relay team) 22 times.

Thorpe's success is based on a strong work ethic, attention to detail, flawless technique, mental strength, and a physiology suited to swimming. At 1.95 m (6 ft 5 in) and 105 kg (231 lb), he is very large for a swimmer and many thought that as he matured and continued to grow he would be unable to maintain his performance as a teenager. He has however, been able to maintain a trademark six-beat kick to power away to victory in the closing stages of races, attributed to his unnaturally large feet.

Thorpe's preparations for the Athens Olympics were clouded by controversy. In late March 2004 Thorpe competed in the qualification events. He was disqualified from the 400 m freestyle (his best event) after making a false start. Australia's Olympic selection rules allow for a qualifier to stand down, and for another swimmer to be selected in their place. After some deliberation, the second qualifier, Craig Stevens, withdrew from the event, and Thorpe accepted the offered place.

Away from the pool, Thorpe in many ways defies the stereotype of Australian sportspeople. He is quiet, mild-mannered, thoughtful, articulate, but extremely guarded in his statements, and he reportedly makes considerable efforts to insulate himself from the media when preparing for and during important events. His lack of interest in (and aptitude for) other sports is well-known. Instead, his other enthusiasm appears to be fashion, as an ambassador for Armani clothing and his own range of designer jewellery.

Thorpe's performances in Sydney and Athens have made him a national hero in Australia, a country which reveres sporting stars. His victory in the 200 metres at Athens pitted him against American swimming phenomenon Michael Phelps, Sydney gold medallist Pieter van den Hoogenband of the Netherlands and his fellow Australian Grant Hackett. The race attracted unprecedented media attention in Australia, and Thorpe's victory made him one of the most celebrated Australian athletes of all time. He has recently bought a $2.9 million house in Caringbah, a southern suburb of Sydney.