Ian James Thorpe (born October 13, 1982) is one of the world's best-ever middle-distance swimmers.

Born in Sydney, Australia, Thorpe has completely dominated the 400 metre freestyle since his first world championship win in 1998, winning the event at the 2000 Summer Olympic Games and the 2001 Fukoka World Championships (at which he won a total of six gold medals). Indeed, his dominance has broadened to include the 200 and 800 metre freestyle (at which he holds the world record), and he is one of the fastest 100 metre freestylers in the world.

Thorpe has also pushed Australian relay teams to unprecedented success, anchoring the winning 4x100 and 4x200 freestyle relay golds in Sydney, the first time the United States has ever been beaten in the events.

In total, Thorpe has broken world records (either individually or as part of a relay team) 22 times.

Thorpe's success is based on his huge, powerful physique. At 195cm and 105 kilograms, he is very large for a swimmer (indeed, many thought that as he matured and continued to grow he would be unable to maintain his performance as a teenager), able to maintain a trademark six-beat kick to power away to victory in the closing stages of races.

Away from the pool, Thorpe in many ways defies the stereotype of Australian sportspeople. At least in public, 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.