Duncan William MacNaughton Scott (born 6 May 1997) is a Scottish swimmer representing Great Britain at the FINA World Aquatics Championships, LEN European Aquatics Championships, European Games and the Olympic Games, and Scotland at the Commonwealth Games. Scott made history after winning four medals - more than any other British athlete at a single Olympic Games - in Tokyo 2020, simultaneously becoming Great Britain's most decorated swimmer in Olympic history. With an additional gold and silver medal in Paris 2024 bringing his total to eight, Scott became Scotland's most-decorated Olympian (surpassing Chris Hoy), and is currently tied with Bradley Wiggins as the second most-decorated Olympian in British history. Scott is the only athlete in the top three to still be actively competing, and the only member of the top four (Hoy, Scott, Wiggins and Jason Kenny) who is not a track cyclist.
An all-rounder in the pool, Scott has swum internationally in 100 and 200 metres freestyle and butterfly, and 200 metres individual medley. He has won gold at the Olympics, three golds at the World Championships in 4 x 200 metre freestyle relay, a World Championship gold in the men's 4 x 100 metre medley relay, as well as silvers at the World Championships and Olympics in freestyle and medley relay. Individually, Scott was the 100 metre freestyle champion at the 2015 European Games and 2018 Commonwealth Games, and the 200 metre freestyle champion at the same European Games and the 2018 European Aquatics Championships. He is an Olympic silver medalist in the individual 200 metres freestyle and 200 metres individual medley, and a World silver medalist in the 200 metres individual medley.
Winning three gold medals in the (100 m and 200 m freestyle, and 4 × 100 m freestyle relay) at the 2015 European Games, he was the most successful British athlete at the Games. A month later, he formed part of the Great Britain squad that won the gold medal at the 2015 World Aquatics Championships in the men's 4 x 200 metre freestyle relay as the 4th leg swimmer in the heat. In 2016, he was a member of the Great Britain team that won silver in the final of the same event at the Olympic Games as well as the men's 4 x 100 metre medley relay. The same team also won the 4 x 100 metre medley relay silver in the 2017 World Championships. A noted relay swimmer, Scott broke the individual British 200 metre freestyle record leading off in the men's 4 x 200 metre relay, before anchoring the team that won gold in 4 x 100 metre medley relay at the 2019 World Championships. His anchor splits in a number of global relays are among the fastest in history - as of 2024, Scott has both the second fastest 100 metre freestyle anchor leg in history, and the third fastest 200 metre freestyle anchor leg.
Scott grew up in Alloa, moving to Strathallan School on a sport scholarship at the beginning of secondary. He trained daily throughout his high school years.
Scott came to public attention when he won eight gold medals at the 2013 Scottish Age Group Championships in Edinburgh. Later that year he competed at the 2013 European Youth Summer Olympic Festival taking gold in the 200 m medley, silvers in the (400 m medley, 4 × 100 m mixed freestyle) and bronze in the 4 × 100 m freestyle.
In July 2014, at the 2014 European Junior Championships, Scott won a gold medal in the (200 m individual medley, 4 × 100 m freestyle) and bronze in the 4 × 200 m freestyle. A few weeks later he won a silver medal in the 4 × 200 m freestyle relay with Scotland at the 2014 Commonwealth Games. He then competed at the 2014 Youth Olympics in Nanjing taking gold in the 4 × 100 m freestyle (with Luke Greenbank, Miles Munro, and Martyn Walton).
At the inaugural 2015 European Games in Baku (a junior event for swimmers), he won three gold medals in the (100 m freestyle, 200 m freestyle and 4 × 100 m freestyle relay) and three silver medals in the 4 × 200 m freestyle, 4 × 100 m mixed freestyle, and 4 × 100 m medley (with Greenbank, Charlie Attwood, and Walton).
In the 2016 Rio Olympics, he won a silver in the 4 × 200 m freestyle relay with Stephen Milne, James Guy, and Dan Wallace. He also won another silver in the 4 × 100 m medley relay with Chris Walker-Hebborn, James Guy and Adam Peaty. He was placed 5th in the final of the individual men's 100 metres freestyle.
In the 2017 World Aquatics Championships. He won gold in the 4 × 200 m freestyle with James Guy, Stephen Milne and Nick Grainger in a time of seven minutes 1.70 seconds. He won a further silver in the 4 × 100 m medley relay at the World Championship with same Olympic line-up of Walker-Hebborn, Guy and Peaty.
At the 2018 Commonwealth Games, Scott won the gold medal in the 100 metre freestyle in a time of 48.02 seconds. He also won four bronze medals at the Games: in the 200 metre butterfly, 200 metre freestyle, 4 × 100 metre freestyle relay, and 4 × 200 metre freestyle relay, and became the first Scottish athlete to win five medals a single Commonwealth Games. He added a sixth medal when he won the silver medal in the 200 metre individual medley.
At the 2018 European Championships, Scott won a silver in the 100 metre freestyle. Later the same day he won gold as part of the relay team in the 4 × 200 metre freestyle relay with Calum Jarvis, Thomas Dean and James Guy. He also won gold in the 200 metre freestyle, despite only having just made the final in 8th place. He added a third gold in the final day of the championships, winning the men's 4 × 100 metre medley relay as part of the British team with Adam Peaty, James Guy and Nicholas Pyle.
On 13 September he was named Scottish Sportsperson of the Year at the Team Scotland Scottish Sports Awards.
At the 2019 World Aquatics Championships held in Gwangju, South Korea, Scott came joint fourth in the 200 m freestyle, but the first-placed finisher Danas Rapšys was disqualified for a false start, and Scott was awarded a bronze medal together with Martin Malyutin. After the medal ceremony, Scott refused to shake hands and take pictures with the gold medallist Sun Yang, who had previously been banned for a trimetazidine drug offence in 2014 for three months and was involved in an ongoing doping case controversy. This transpired following Australian Mack Horton's refusal to share a podium with Sun at the medal ceremony when the Chinese national anthem was played. Both Sun and Scott were given official warnings from FINA; Scott was subjected to death threats from Sun's fans on social media.
In the lead-off leg in the men's 4 × 200 m freestyle relay final, Scott broke the British national record with a time of 1:44:91; the team finished fifth in the race. In the men's 4 × 100 metre medley relay together with Adam Peaty, James Guy and Luke Greenbank, he swam the anchor leg in 46.14 seconds, the second fastest freestyle relay split of all time, and the fastest in textile. He managed to overcome a 1.11 second deficit to finish in front of the United States team, thereby winning Britain's first gold medal in the event in the World Championships in a European record time of three minutes, 28.10 seconds.
Scott competed for London Roar during the 2020 International Swim League once again and during the tournament in Budapest he set a new British Record in the 200 Individual Medley and broke the British Record for the 200m freestyle twice, a week apart from each other.
Based on his 2019 individual world championship result, Scott was pre-selected for the postponed 2020 Tokyo Olympics.
At the 2021 British Swimming Olympic trials, Scott broke the British record in the 200m individual medley with a time of 1:55.90. In May 2021, Scott won a silver medal in 200m freestyle at the European Championships. He also won two gold medals in the men's 4 x 100 m medley and mixed 4 × 100 metre freestyle relays, as well as two silvers in the men's 4 × 100 metre freestyle and 4 × 200 metre freestyle relays.
At the 2021 British Championships, Scott set a new British Record of 1:55:90 in the 200IM, then went onto equal his existing British Record in the 100m Freestyle and finished off with a new British Record in the 200m Freestyle with a time of 1:44:47.