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.
The 4 × 400 metres relay or long relay is an athletics track event in which teams consist of four runners who each complete 400 metres or one lap. It is traditionally the final event of a track meet. At top class events, the first leg and the first bend of the second leg are run in lanes. Start lines are thus staggered over a greater distance than in an individual 400 metres race; the runners then typically move to the inside of the track. The slightly longer 4 × 440 yards relay, on an Imperial distance, was a formerly run British Commonwealth and American event, until metrication was completed in the 1970s.
Michael Mathieu is a retired Bahamian sprinter from Freeport, Grand Bahama who specialized in the 200 metres and 400 metres. He was part of the Bahamian silver medal-winning team in the men's 4×400 metres relay at the 2008 Beijing Olympics, running second leg and recording a 44.0 split, and the gold medal-winning team at the 2012 Summer Olympics. He was also a part of second place relay team at the 2007 World Championships. He won the bronze medal in the 4x400 metres relay in the 2016 Summer Olympics.
Jonathan Borlée is a Belgian sprinter, who specializes in the 400 metres. He is a member of the Borlée family.
Jereem Richards is a Trinidadian track and field sprinter who specializes in the 200 metres and 400 metres events. He won the bronze medal in the 200 m at the 2017 World Championships in Athletics and gold for the 400 m at the 2022 World Indoor Championships. Richards took 200m titles at both the 2018 and 2022 Commonwealth Games. He was part of the Trinidad and Tobago team that won the bronze medal in the men's 4 × 400 m relay at the 2012 World Indoor Championships and a gold medal at the 2017 World Championships in Athletics.
Steven Solomon is an Australian Olympic sprinter. He is a six-time defending Australian 400 metres champion.
Shaunae Miller-Uibo is a Bahamian track and field sprinter who competes in the 200 and 400 metres. She is a two-time Olympic champion after winning the women's 400 metres at the 2016 Rio Olympics and again at the 2020 Tokyo Olympics.
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.
Samuel Harrison Carter is a Paralympic athlete, who competes in 100m, 200m, 400m T54 events. He has represented Australia at the 2016 Rio Paralympics and 2020 Tokyo Paralympics.
William "Woody" Kincaid is an American long-distance runner. He won the gold medal in the 5000 meters at the 2022 NACAC Championships. Kincaid is the North American indoor record holder for that event.
Fredrick Lee Kerley is an American professional track and field sprinter who started his career competing in the 400 meters until 2020, when he transitioned to the 100 meters and 200 meters. He has earned several medals at the World Championships in the 400 m and 4 × 400 m relay including an individual bronze and a relay gold at the 2019 edition. Kerley claimed 100 m gold in the 2022 edition.
Emmanuel Kipkurui Korir is a Kenyan middle-distance runner. He is the 2020 Tokyo Olympic and 2022 World champion in the 800 metres. Korir won the silver medal in the event at the 2018 African Championships in Athletics.
The men's 400 metres event at the 2020 Summer Olympics took place between 1 and 5 August 2021 at the Olympic Stadium. Approximately fifty athletes were expected to compete; the exact number was dependent on how many nations use universality places to enter athletes in addition to the 48 qualifying through time or ranking. 48 athletes from 33 nations competed. The event was won by Steven Gardiner of the Bahamas, with Anthony Zambrano of Colombia taking silver. Those were the first medals in the men's 400 metres for each of those two nations. Kirani James of Grenada won his third consecutive medal in the event with his bronze, making him the first man to earn three medals in the 400 metres.
Trevor Stewart is an American Olympic athlete. He won a bronze medal in the Mixed 4 x 400 metres relay at the 2020 Summer Games.
Bryce Deadmon is an American track and field athlete. In July 2023, he became US national champion in the 400 meters.
Elija Godwin is an American athlete who specialises in the 400 metres.
David Kendziera is an American Olympic athlete who runs the 400m hurdles and 110m hurdles.
Sean Bailey is a Jamaican athlete.
Alexander (Alex) Beck is an Australian Olympic athlete. He is a three time defending National champion.
Quincy Hall is an American track and field athlete who competes over 400 metres and 400m hurdles.
