Vania Stambolova is a Bulgarian athlete. She competes in the 400 m hurdles and the 400 m event. At the 2006 IAAF World Indoor Championships she won a silver medal over 400 m. She also won a gold medal at the 2006 European Championships. At present, Stambolova is the highest paid female athlete in Bulgaria.
Adolphus "Dolly" Jones is a Kittitian and Nevisian track and field athlete and soccer player.
Erkinjon Tulkinovich Isakov is a retired Uzbekistani athlete who competed in the 400 metres hurdles before moving up to middle distance events. He twice represented his country at the Olympic Games, in 2000 and 2004, failing to advance to the semifinals.
Nicholas Wachira is a Kenyan former middle-distance runner who competed mostly in the 800 metres. He represented his country at the 2001 and 2003 World Championships reaching semifinals at both occasions. In addition, he won gold medals at the 1999 World Youth and 2000 World Junior Championships.
Yasmani Copello Escobar is a Cuban-born track and field hurdler who represents Turkey internationally. His personal best for the 400 metres hurdles is 47.81 seconds, set in the final of the 2018 European Athletics Championships in Berlin.
Markku Aulis Taskinen is a Finnish former athlete. At the 1974 European Championships he won bronze medals in both the 800 metres and the 4 × 400 metres relay. He was European indoor champion at 800 metres in 1978.
Ester Goossens is a retired Dutch athlete who competed in a variety of events, including the 400 metres, 800 metres and 400 metres hurdles. She represented her country at the 1997 World Championships and 1999 World Indoor Championships.
Kendra "Keni" Harrison is an American hurdler. Harrison set the world record in the women's 100 metres hurdles with a time of 12.20 seconds on July 22, 2016 at the London Müller Anniversary Games, breaking the world record of 12.21 seconds set nearly 28 years earlier by Bulgarian athlete Yordanka Donkova.
Nicholas Kiplagat Bett was a Kenyan track and field athlete who competed in the 400 metres hurdles. His personal best for the event is 47.79 seconds. He was a world champion in the event, having won in 2015, and a two-time bronze medallist at the African Championships in Athletics. He died in a road accident in Kenya at the age of 28.
Byron Robinson is an American track and field athlete who competes in the 400 metres hurdles. He holds a personal record of 48.58 seconds for the event. He was the runner-up at the United States Olympic Trials in 2016.
Manlio Molinari is a retired Sammarinese athlete who competed in the 400 and 800 metres. He represented his country at four consecutive Summer Olympics, starting in 1984.
Viktors Lācis is a Latvian retired middle-distance runner who specialised in the 800 metres. He represented his country at the 2000 Summer Olympics, as well as two World Championships. He later also competed in the 400 metres hurdles.
Ricardo Cunningham is a Jamaican middle-distance runner turned 400 metres hurdler. He represented his country at the 2017 World Championships as well as the 2015 Pan American Games and two Commonwealth Games.
Richard Davenport is an English former sprinter who specialised in the 400 metres. He won a silver medal in the 4 × 400 metres relay at the 2005 European Indoor Championships.
Youssef Mohammed Karam Taher is a Kuwaiti sprinter specialising in the 400 metres and 400 metres hurdles. He represented his country at the 2018 World Indoor Championships reaching the semifinals.
Rai Benjamin is an American professional hurdler and sprinter specializing in the 400 m and 400 m hurdles. He is the second fastest man in history in the 400 m hurdles with a personal best time of 46.17 s. He won a silver medal at his first Olympic Games in 2021 and at the World Championships in 2019 in the men's 400 m hurdles, and gold medals in the 4 × 400 m relay at the same competitions.
Quentin Jarrod Iglehart-Summers is an American former track and field sprinter, who specialized in the 400-meter dash. He set a personal record of 45.46 seconds for the event in 2008. He was a gold medalist in the 4 × 400 metres relay at the IAAF World Indoor Championships in 2012. He also won a relay gold medal at the 2006 World Junior Championships in Athletics. At collegiate level he was a four-time national champion in the relay with the Baylor Bears.
Kenneth Selmon is an American track and field athlete who specializes in the 400 metres hurdles. He won the USA Outdoor Championship in 2018 and represented his country at the 2018 Athletics World Cup in London, where he won the 400 metres hurdles.
Carl Bengtström is a Swedish athlete in the 400 metres and 400 metres hurdles. He represented his country at the 2021 European Indoor Championships finishing fourth in the final and narrowly missing a medal. He earlier won a gold medal at the 2019 European U20 Championships.
Kenya 
