Roger Anthony BlackMBE is an English former athlete who competed internationally for Great Britain and England. During his athletics career, he won individual silver medals in the 400 metres sprint at both the Olympic Games and World Championships, two individual gold medals at the European Championships, and 4 × 400 metres relay gold medals at both the World and European Championships.
André Lamar Phillips is a retired American track and field athlete who is best known for winning the 400 metres hurdles gold medal at the 1988 Olympic Games.
Sunday Bada was a Nigerian sprinter who specialized in the 400 metres event. He won three medals at the World Indoor Championships, including a gold medal in 1997. His personal best time was 44.63 seconds, and with 45.51 seconds indoor he holds the African indoor record. He set a national record in the 4 x 400 metres relay at the 2000 Olympics, where the Nigerian team also won gold medals after the disqualification of the US.
Louis Jacobus van Zyl, better known as L. J. van Zyl, is a South African athlete competing in the 400 metre hurdles. He is the South African record holder in the event with a personal best of 47.66 seconds, which he achieved twice, three months apart. His time ranks him in the all-time top 25. He is a three-time African Champion in the event and competed for his country at the 2008, 2012 and 2016 Summer Olympics.
LaShawn Merritt is an American track and field athlete who competes in sprinting events, specializing in the 400 metres. He is a former Olympic champion over the distance and his personal best of 43.65 seconds makes him the ninth fastest of all time.
David Lekuta Rudisha, MBS is a Kenyan middle-distance runner who specialized in the 800 metres. He is a two-time back-to-back Olympic champion from the 2012 London and 2016 Rio Olympics, a two-time World champion from the 2011 and 2015 World Championships in Athletics, and world record holder at the event with a time of 1:40.91 set at the 2012 London Games on 9 August 2012. Rudisha is the first and only person to ever run 800 metres under 1:41, and he holds the three fastest, six of the eight fastest, and half of the twenty fastest times ever run in this event.
Rabah Mahhamed Yousif Bkheit (born 11 December 1986) is a Sudanese-born British track and field athlete, who initially competed for Sudan before obtaining British citizenship.
Isaac Makwala is a Botswana sprinter who specializes in the 400 metres.
Kirani James is a Grenadian professional sprinter who specializes in the 200 and 400 metres. He won the 400 m at the World Championships in 2011, and the 2012 London Olympics. In the 400 metres, James also won the silver medal at the 2016 Rio Olympics, and bronze medal at the 2020 Tokyo Olympics, thus becoming the first man to earn the full set of three medals in the centennial history of the event. He is Grenada's first and only Olympic medalist.
Pál Joensen is a Faroese elite swimmer. He was born in Vágur, Suðuroy, Faroe Islands. He has won World and European Championship medals. His bronze medal in the men's 1500 metre freestyle at the 2012 FINA World Swimming Championships in Istanbul was the first medal won by a Faroese swimmer at the World Aquatic Championships.
Chad Guy Bertrand le Clos, OIS is a South African competitive swimmer who is an Olympic, World and Commonwealth Games champion. He is the African record, Commonwealth record, and South African record holder in the short course and long course 200-metre butterfly and the short course 100-metre butterfly. He also holds the African records and South African records in the long course 200-metre freestyle and 100-metre butterfly, and the short course 100-metre freestyle. Formerly, he was a world record holder in the short course 100-metre butterfly and 200-metre butterfly.
Ismail Al-Sabiani is a Saudi Arabian track and field athlete who specialises in the 400 metres.
Yousef Ahmed Masrahi is a Saudi Arabian track and field athlete, who specialises in the 400 metres sprint. His personal best time for the event is 43.93 seconds, set in 2015, and is the Asian record.
Lalonde Keida Gordon, HBM is a Tobagonian male track and field sprinter who specialises in the 400 metres. He won the bronze medal at the 2012 London Olympics with a personal best of 44.52 seconds. He is the third fastest 400 m runner from his country after Machel Cedenio and Ian Morris.
Taoufik Makhloufi is an Algerian athlete who specialises in middle-distance running. He became the 1500 metres Olympic champion at the 2012 Summer Olympics in London, England. In 2016, Makhloufi took the silver medal in the 800m and 1500 m at the Summer Olympics in Rio, Brazil.
Matthew Hudson-Smith is a British track and field sprinter who specialises in the 400 metres. He holds, as of August 2023, the British and European record, running a personal best of 44.26 seconds for the distance set at the Budapest World Championships in 2023. He was the 2018 European Champion in 400 metres, and a member of the gold-winning teams in the 4 x 400 metre relay at the 2014 European Athletics Championships, with Great Britain and 2014 Commonwealth Games with England.
Janieve Russell is a Jamaican track and field athlete who competes mainly in the 400 metres hurdles and the 400 metres sprint. She won an Olympic bronze medal in the 4 × 400 m relay in Tokyo 2021, where she also finished fourth in the 400m hurdles final in a personal best of 53.08 secs. She is a four-time Commonwealth Games gold medallist, winning the 400m hurdles title in 2018 and 2022, and the 4 × 400 m relay in 2014 and 2018. She has also won two relay silvers at the World Championships and a relay gold at the World Indoor Championships.
Mohamed Ali Gouaned is an Algerian middle-distance runner specializing in the 400 meters and 800 meters. He holds the Junior World best in 600 meters with a time of 1:14:79 set in Algiers on 26 March 2021 breaking the record held by Wilfred Bungei since 1 September 1999 with a time of 1:14:94.
Ahmed Ayoub Hafnaoui is a Tunisian swimmer. He is the African record holder in the long course 400-metre and 1500-metre freestyle, and the short course 800-metre and 1500-metre freestyle events. He competed in the 2020 Summer Olympics, where he won a gold medal in the men's 400-metre freestyle. He ranked No. 16 in the world and was the slowest qualifier for the final race but won Olympic gold with a time of 3:43.36. Hafnaoui was the only Tunisian to win Olympic gold at Tokyo 2020.
Matthew "Matt" Sates is a South African swimmer. He is the African record holder in the short course 200 metre freestyle, 400 metre freestyle, and 200 metre individual medley as well as the South African record holder in the 400 metre individual medley. He is the 2022 World Short Course champion in the 200 metre individual medley and bronze medalist in the 400 metre individual medley. At the 2022 NCAA Division I Championships, he won the NCAA title in the 500 yard freestyle. For the 2021 FINA Swimming World Cup, he was the overall male winner, earning a total of 18 medals, including 13 gold medals.
Libya 
