The 400 metres, or 400-meter dash, is a sprint event in track and field competitions. It has been featured in the athletics programme at the Summer Olympics since 1896 for men and since 1964 for women. On a standard outdoor running track, it is one lap around the track. Runners start in staggered positions and race in separate lanes for the entire course. In many countries, athletes previously competed in the 440-yard dash (402.336 m)—which is a quarter of a mile and was referred to as the 'quarter-mile'—instead of the 400 m (437.445 yards), though this distance is now obsolete.
James Stephen Baulch is a retired Welsh sprint athlete and television presenter. He won the 400 metres gold medal at the 1999 World Indoor Championships. As a member of British 4 × 400 metres relay teams, he won a gold medal at the 1997 World Championships, and silver medal at the 1996 Olympic Games. He represented Wales at the Commonwealth Games where he won an individual silver and a bronze medal in the 4 × 400 m relay.
Alistair Ian Cragg is an international track and field athlete.
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.
Leslie Djhone is a French track and field athlete who competes in the 400 metres and 4 x 400 metres relay.
Paul ("Junior") McKee is an Irish sprint athlete. He has represented Ireland many times in international competition, including being a member of the Irish 4 x 400 metres relay team at the Sydney Olympics. He has also represented Northern Ireland, at the Commonwealth Games.
Andrea Barberi was an Italian sprint athlete who specialized in the 400 metres.
Joanne Cuddihy is an Irish sprint athlete, competing for the Kilkenny City Harriers. She was the Irish 400 metres outdoor women's record holder with a time of 50.73 seconds.
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.
Richard Thomas Buck is a former British sprinter who specialised in the 400 metres event. He is from York, and trains in Loughborough. Buck's current club is City of York A.C.. Previously, he had an 18-month spell at Scarborough A.C. He has been trained by his grandfather, Geoff Barraclough, and is now coached by Nick Dakin.
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.
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.
Michael Bingham is an American-born British 400 metres track and field athlete. The silver medalist in the individual 400 metres at the 2010 European Championships, his most notable successes came as a long-time member of the Great Britain and England 4 x 400 metre relay squads. A European indoor, European outdoor and Commonwealth Games champion in the long relay, Bingham won medals at every major indoor and outdoor championships available to him, winning Olympic bronze in 2008, World outdoor silver and World indoor silver (twice), in addition to the gold medals at European and Commonwealth Games level.
Pavel Maslák is a Czech sprinter who specialises in the 200 metres and 400 metres. He is the only athlete in history who has managed to win the 400 m title at the World Indoor Championships at three consecutive championships. Maslák is the first Czech to have run 400 metres under 45 seconds outdoor and under 46 seconds indoor.
Steven Solomon is an Australian Olympic sprinter. He is a six-time defending Australian 400 metres champion.
Tony McQuay is an American track and field athlete who specializes in the 400 meters. He is a member of the 2012 and 2016 United States Olympic teams, winning a silver medal in the 4 × 400 m relay in 2012 and a gold in the same event in 2016. He is also a two time World Champion in this event.
David Verburg is an American track and field athlete who specializes in the 400 meters. He holds gold medals in the 4 × 400 m relay from the 2016 Olympics; the 2013 and 2015 World Championships; and the 2014 Indoor World Championships.
Abdalelah Haroun Hassan was a Qatari track and field sprinter. He specialised in the 400 metres. He was the 2015 Asian champion in the event and holds the Asian indoor record.
Christopher O'Donnell is an Irish track and field athlete competing in sprinting events. He represented Ireland at the 2020 Summer Olympics in the Mixed 4 x 400m relay where he was part of the first ever Irish team to run in an Olympic final, and was also part of the team who reached the final of the 2022 and 2023 World Championships. He is the current Irish U20 record holder in the 400 metres, with a time of 46.54, set on 22 July 2017 at the European U20 Championships, where he finished 6th in the final. His personal best of 45.26 seconds sits joint-2nd on the Irish all-time list and he is a 5-time National 400m champion.
Rhasidat Adeleke is an Irish sprinter. She won the 100 metres / 200 m double at the 2021 European Athletics Under-20 Championships.
Ireland 
