Thomas Ceccon (Italian pronunciation: [ˈtɔːmas tʃekˈkon]; born 27 January 2001) is an Italian swimmer. He is a world record holder in the long course 100 metre backstroke and the short course 4×100 metre freestyle relay. He is also the Italian record holder in the long course 50 metre backstroke and 50 metre butterfly. He is the 2022 World champion in the 100 metre backstroke and 2022 European champion in the 100 metre backstroke and 50 metre butterfly. In the 100 metre individual medley, he won the gold medal at the 2022 World Short Course Championships and the bronze medal at the 2021 World Short Course Championships. At the 2020 Summer Olympics, he won a silver medal in 4×100 metre freestyle relay, a bronze medal in the 4×100 metre medley relay, placed fourth in the 100 metre backstroke, and placed twelfth in the 100 metre freestyle. On 29 July 2024 he won gold for the 100m backstroke in the 2024 Summer Olympics. He also earned a bronze medal in the men’s 4×100 metre freestyle relay at the same Games. ^{[AI-retrieved source]} In April  2025 at the Australian Open Swimming Championships, Ceccon set a new Italian record in the 200 metre backstroke with a time of 1:55.71. At the 2025 World Aquatics Championships in Singapore, he won silver in the men’s 100 metre backstroke and bronze in the men’s 50 metre butterfly.

Ceccon was born in Thiene, in the province of Vicenza, Italy on 27 January 2001. He trains under the guidance of coach Alberto Burlina for Gruppo Sportivo Fiamme Oro. He has retained the Italian record in the long course 100 metre backstroke, since 17 December 2020, starting with a 52.84.

He won the 50 m free style Youth Olympic title and 4 other medals at 2018 Youth Olympic Games in Buenos Aires. He participated to the 2019 World Aquatics Championships. He won two gold medals at the 2019 FINA World Junior Swimming Championships.

At the 2020 Summer Olympics, held in 2021 due to the COVID-19 pandemic and contested in Tokyo, Japan, Ceccon won a silver medal in the 4×100 metre freestyle relay on the second day of competition, contributing a split of 47.45 seconds for the second leg of the relay to help finish second in an Italian record time of 3:10.11. For the 100 metre backstroke, he placed fourth in the morning final on day three with an Italian record time of 52.30 seconds, after setting an Italian record of 52.49 seconds in the preliminary heats on day one. In the evening of day three, he swam a personal best time of 47.71 seconds in the preliminary heats of the 100 metre freestyle to qualify for the semifinals ranking first. The following day, in the semifinals, he went on to place twelfth with a time of 48.05 seconds, which was 0.94 seconds slower than the fastest swimmer in the semifinals Kliment Kolesnikov of Russia, and did not advance to the event final.

On 31 July, Ceccon helped achieve a fourth-place finish in the 4×100 metre mixed medley relay, swimming the backstroke portion of the relay in 52.23 seconds to contribute to the final mark, and Italian record time, of 3:39.28. The following day, he won a bronze medal as part of the 4×100 metre medley relay, finishing in an Italian record time of 3:29.17 with finals relay teammates Nicolò Martinenghi (breaststroke), Federico Burdisso (butterfly), and Alessandro Miressi (freestyle).

On day one of the 2021 World Short Course Championships, held in December at Etihad Arena in Abu Dhabi, United Arab Emirates, Ceccon placed ninth in the semifinals of the 100 metre backstroke with a time of 50.22 seconds. In the same session, he split a 45.71 for the second leg of the 4×100 metre freestyle relay to help win the silver medal in an Italian record time of 3:03.61. Three days later, he started the evening session off with a bronze medal in the 100 metre individual medley with a time of 51.40 seconds and a placing of twelfth in the semifinals of the 50 metre butterfly with a time of 22.74 seconds. For his third and final event of the evening, he helped set a new Italian record of 6:51.48 in the final of the 4×200 metre freestyle relay to place fourth, splitting a 1:44.23 for the second leg of the relay. The second-to-last day of competition, he won a bronze medal in the 4×50 metre medley relay, contributing a split of 21.11 for the freestyle leg of the relay in the preliminaries before being substituted out for Lorenzo Zazzeri in the final. On the final day, he split a 50.96 for the backstroke portion of the 4×100 metre medley relay in the preliminaries before Lorenzo Mora substituted in for him on the finals relay and all relay members won a gold medal when the finals relay finished first in 3:19.76.

At the 2022 World Aquatics Championships, held in June in Budapest, Hungary, Ceccon won a bronze medal as part of the 4×100 metre freestyle relay on the first day of pool swimming competition. For the 50 metre butterfly, Ceccon placed fifth in the final on day two with a time of 22.86 seconds, after setting a new Italian record time of 22.79 seconds in the semifinals to qualify for the final ranking second. One day later, day three, he won the gold medal in the 100 metre backstroke with a world record time of 51.60 seconds. His world record was the first world record set in swimming at the 2022 World Aquatics Championships. On the fourth day, he helped place fifth in the 4×100 metre mixed medley relay, leading off the relay with a 52.26 for the backstroke portion of the relay to contribute to the final time of 3:41.67.

In the 50 metre backstroke final on day eight, Ceccon won the bronze medal and received his medal at the medals ceremony before a swimmer from the United States who was disqualified for an illegal finish during the race had his disqualification overturned and bumped the bronze medal from Ceccon to Ksawery Masiuk of Poland. The same day, he won a gold medal in the 4×100 metre medley relay, splitting a 51.93 for the backstroke leg of the relay in the final to help achieve a European record time of 3:27.51.