[22] In 1995, Thorpe started his secondary education at East Hills Boys Technology High School[11][23] and switched coaches to swim alongside his sister under the tutelage of Doug Frost.

[28] At the New South Wales Championships in January 1997, Thorpe's time of 3 min 59.43 s in the 400 m was eight seconds faster than his previous personal best;[28] it made him the first 14-year-old to cover the distance in less than four minutes on Australian soil.

With a top-three finish and a specific qualifying time required for selection, Thorpe focused on the 400 m freestyle after injuries to world record holder Kieren Perkins and Daniel Kowalski; both had won Olympic medals in the event.

Along with teammates Michael Klim, Ian van der Wal and Hackett, Thorpe claimed silver, making him the youngest ever Pan Pacific medalist.

[3][35][36][42] As a result of the media attention generated by his win on home soil, Thorpe received multiple offers for television commercials and was often surrounded by autograph hunters.

[3][4][35][71][72][73] Immediately after the Pan Pacific Championships, Thorpe's management announced his signing to Adidas for an undisclosed six-figure sum, stating that he would race in their new bodysuit.

[78] Thorpe embarked on a European FINA World Cup tour to hone his racecraft, but this was overshadowed by comments made by German head coach Manfred Thiesmann accusing him of using steroids.

[79][80][81] Thiseman claimed that Thorpe's physical attributes were symptomatic of steroid use and that his ability to exceed prior records believed to be drug-fuelled made his feats worthy of suspicion.

[31][79] Thorpe's difficulties heightened at the subsequent German leg of the tour in Berlin, when a standoff over a drug-test arose when officials wanted to take an unsealed sample due to lack of containers.

[4][95][96][97] His attempt to secure a third individual berth failed after he finished fourth in the final of the 100 m and withdrew from the 1500 m.[98][99][100] Entering the Olympics, the Australian public expected Thorpe to deliver multiple world records and gold medals as a formality; Sydney's Daily Telegraph posted a front-page spread headlined Invincible.

[109] Thorpe lined up later in the night alongside Klim, Chris Fydler and Ashley Callus to anchor the 4 × 100 m freestyle relay, an event which the Americans had never lost at Olympic level.

When Thorpe broke the 200 m freestyle Olympic record in the heats the following morning,[115] his main rival Pieter van den Hoogenband of the Netherlands (with World No.

As a result of starting harder than usual, Thorpe faded as van den Hoogenband drew away to claim gold and equal his world record, stunning the home crowd.

[4][128][129] Thorpe's performances as Australia's leading medalist for the Games were recognised when the Australian Olympic Committee granted him the honour of carrying the flag at the closing ceremony.

Thorpe fell behind in the early half of the leg before kicking away in the closing stages, to seal gold with his fastest-ever relay split of 47.87 s.[147][148] In the 800 m final, he shadowed Hackett for the first 750 m, staying within a body length.

After Matt Welsh, Regan Harrison and Geoff Huegill had finished their legs, Thorpe's change left him half a body length behind the new 100 m world champion Anthony Ervin of the United States.

[164] On the first night in Manchester, Thorpe again lowered his 400 m mark by 0.09 s to 3 min 40.08 s, which remains the fastest ever 400m swim not swum in an LZR Racer[4][160][165] before anchoring the 4 × 100 m freestyle relay team to another gold.

[166][169][170] When he collected a silver in his first international race in the 100 m backstroke with another personal best behind world champion Matt Welsh,[171] he was forced to rebuff media comparisons to Spitz.

[182] Thorpe found some relief by setting a new Commonwealth record of 2 min 00.11 s in his first long course 200 m individual medley outing, the fifth fastest time in the past year.

[199] Thorpe again anchored the 4 × 200 m freestyle team to retain the world title along with Hackett, Nicholas Sprenger and Craig Stevens, with a reduced margin over the Americans, who finished less than two seconds in arrears.

[203] In late March 2004 at the Australian Championships in Sydney, Thorpe overbalanced whilst on the blocks in the heats of the 400 m freestyle and fell into the water, resulting in his disqualification and ending the defence of his Olympic 400 m title.

[210] The 200 m began with van den Hoogenband again attacking immediately, reaching the 100 m mark more than a second under the world record split, with Thorpe half a body length behind.

[212] The next day saw six years of Australian victory in the 4 × 200 m freestyle relay ended when Hackett, Klim and Sprenger had put Thorpe into the final leg 1.48 s behind Keller.

[220][221] Thorpe's illness was later diagnosed as a strain of glandular fever,[222] and after a further delay caused by a broken hand, he moved to the United States in July to work with Dave Salo.

The Australian Sports Anti-Doping Authority (ASADA) confirmed that they had investigated Thorpe in the past, for abnormal levels of testosterone and luteinising hormone (LH), but had dismissed the result.

It was subsequently announced that Thorpe was targeting qualification for the 2013 World Championships in Barcelona[239] and later the 2014 Commonwealth Games in Glasgow,[240] but was forced to abandon his plans due to a shoulder injury.

[242] Thorpe was known for using his trademark six-beat kick to power away from his rivals in the closing stages of races, the effectiveness of which was attributed to his unusually large size 17 feet.

[262] In a July 2014 televised interview with British talk show host Michael Parkinson, Thorpe came out as gay, after years of denying his homosexuality publicly.

[276][277] In September 2020, the International Olympic Committee published a question and answer format interview with Thorpe, which touched on his sexual orientation and some of the challenges he faced due to his homosexuality in competitive swimming.

In the lead-up, Thorpe visited Japan to promote Asahi in a series of television events,[7][290] and upon returning for the competition, he was mobbed at the airport by youthful crowds 25 m deep; hundreds camped outside the Australian team's hotel.