Athletics at the 2020 Summer Olympics – Men's 400 metres hurdles

This will be the 27th appearance of the event, which is one of 12 athletics events to have been held at every Summer Olympics. It had been introduced along with the men's 200 metres hurdles in 1900, with the 200 being dropped after 1904 and the 400 being held through 1908 before being left off the 1912 programme. However, when the Olympics returned in 1920 after World War I, the men's 400 metres hurdles was back and would continue to be contested at every Games thereafter.

The reigning world champion is Karsten Warholm of Norway. The reigning Olympic champion is Kerron Clement, who is 35 years old, has not competed in the long hurdles since July 2019, and has not met the qualifying standard.[3]

A National Olympic Committee (NOC) could enter up to 3 qualified athletes in the men's 400 metres hurdles event if all athletes meet the entry standard or qualify by ranking during the qualifying period. (The limit of 3 has been in place since the 1930 Olympic Congress.) The qualifying standard is 48.90 seconds. This standard was "set for the sole purpose of qualifying athletes with exceptional performances unable to qualify through the IAAF World Rankings pathway." The world rankings, based on the average of the best five results for the athlete over the qualifying period and weighted by the importance of the meet, will then be used to qualify athletes until the cap of 40 is reached.[2][4]

The qualifying period was originally from 1 May 2019 to 29 June 2020. Due to the COVID-19 pandemic, the period was suspended from 6 April 2020 to 30 November 2020, with the end date extended to 29 June 2021. The world rankings period start date was also changed from 1 May 2019 to 30 June, 2020; athletes who had met the qualifying standard during that time were still qualified, but those using world rankings would not be able to count performances during that time. The qualifying time standards could be obtained in various meets during the given period that have the approval of the IAAF. Only outdoor meets are eligible. The most recent Area Championships may be counted in the ranking, even if not during the qualifying period.[2][5]

NOCs can also use their universality place—each NOC can enter one male athlete regardless of time if they had no male athletes meeting the entry standard for an athletics event—in the 400 metres hurdles.[2]

The event will continue to use the three-round format used previously in every Games since 1908 (except the four-round competition in 1952).[6]

Prior to this competition, the existing world, Olympic, and area records are as follows.

World record	Kevin Young (USA)	46.78	Barcelona, Spain	6 August 1992
Olympic record	Kevin Young (USA)	46.78	Barcelona, Spain	6 August 1992

Area	Time (s)	Athlete	Nation
Africa (records)	47.10	Samuel Matete	Zambia
Asia (records)	46.98	Abderrahman Samba	Qatar
Europe (records)	46.87[7]	Karsten Warholm	Norway
North, Central America and Caribbean (records)	46.78 WR	Kevin Young	United States
Oceania (records)	48.28	Rohan Robinson	Australia
South America (records)	47.84	Bayano Kamani	Panama

All times are Japan Standard Time (UTC+9)