The 400 metres hurdles is a track and field hurdling event. The event has been on the Olympic athletics programme since 1900 for men and since 1984 for women.
The men's 400 metres hurdles at the 2004 Summer Olympics as part of the athletics program were held at the Athens Olympic Stadium from August 23 to 26. There were 35 competitors from 24 nations. The event was won by Félix Sánchez of the Dominican Republic, the nation's first medal in the men's 400 metres hurdles. Silver went to Danny McFarlane of Jamaica, returning to the podium in the event for the first time since 1992. Naman Keïta's bronze was France's first medal in the event in over 100 years; the last Frenchman to medal in the long hurdles was Henri Tauzin in 1900. The United States' five-Games gold medal streak ended; for only the second time in the history of the event, Americans competed but won no medals.
The Women's 400 metres hurdles event at the 2011 World Championships in Athletics was held at the Daegu Stadium on August 29, 30 and September 1.
The women's 400 metres hurdles at the 2013 World Championships in Athletics was held at the Luzhniki Stadium on 12–15 August.
The 2019 IAAF World Athletics Championships was the seventeenth edition of the biennial, global athletics competition organised by the International Association of Athletics Federations (IAAF), since renamed World Athletics. It was held between 27 September and 6 October 2019 in Doha, Qatar, at the renovated multi-purpose Khalifa International Stadium, but reduced to 21,000 available seats. 1,772 athletes from 206 teams competed in 49 athletics events over the ten-day competition, comprising 24 events each for men and women, plus a mixed relay. There were 43 track and field events, 4 racewalking events, and 2 marathon road running events. The racewalking and marathon events were held in Doha Corniche.
The men's 400 metres hurdles event at the 2016 Summer Olympics took place between 15–18 August at the Olympic Stadium. There were 47 competitors from 33 nations. The event was won by Kerron Clement of the United States, the nation's 19th victory in the men's long hurdles. Clement became the ninth man to win multiple medals in the event. Both Kenya and Turkey earned their first medals in the men's 400 metres hurdles, the former with Boniface Mucheru Tumuti's silver and the latter with Yasmani Copello's bronze.
The men's 400 metres hurdles at the 2015 World Championships in Athletics was held at the Beijing National Stadium on 22, 23 and 25 August.
The women's 400 metres hurdles at the 2015 World Championships in Athletics was held at the Beijing National Stadium on 23, 24 and 26 August.
The men's 400 metres hurdles at the 2017 World Championships in Athletics was held at the London Olympic Stadium on 6–9 August.
The women's 400 metres hurdles at the 2017 World Championships in Athletics was held at the London Olympic Stadium on 7−8 and 10 August.
The men's 400 metres hurdles event at the 2020 Summer Olympics took place between 30 July and 3 August 2021 at the Olympic Stadium. 36 athletes from 26 nations competed.
The men's 400 metres at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha on 1, 2 and 4 October 2019. The winning margin was 0.67 seconds which as of 2024 is the greatest winning margin in the men's 400 metres at these championships since the retirement of Michael Johnson.
The men's 800 metres at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha from 28 September to 1 October 2019.
The men's 110 metres hurdles at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha from 30 September to 2 October.
The women's 400 metres hurdles at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha, Qatar, from 1 to 4 October 2019.
The men's 4 × 400 metres relay at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha, Qatar, from 5 to 6 October 2019.
The men's 400 metres hurdles at the 2022 World Athletics Championships was held at the Hayward Field in Eugene from 16 to 19 July 2022.
The women's 400 metres hurdles at the 2022 World Athletics Championships was held at the Hayward Field in Eugene, Oregon, United States, from 19 to 22 July 2022. It was won by Sydney McLaughlin in a world record time of 50.68 seconds. The winning margin was 1.59 seconds which as of 2024 stands as the greatest winning margin for the women's 400 metres hurdles at these championships.
The men's 400 metres hurdles at the 2023 World Athletics Championships was held at the National Athletics Centre in Budapest, Hungary from 20 to 23 August 2023.
The men's 400 metres hurdles at the 2024 Summer Olympics was held in four rounds at the Stade de France in Paris, France, from 5 to 9 August 2024. This was 28th time that the men's 400 metres hurdles was contested at the Summer Olympics. A total of 40 athletes were able to qualify for the event by entry standard or ranking.
