The men's 400 metres competition at the 2012 Summer Olympics in London, United Kingdom, was held at the Olympic Stadium on 4–6 August. Forty-nine athletes from 38 nations competed. The event was won by 0.52 seconds by Kirani James of Grenada, earning the country its first Olympic medal. Luguelín Santos's silver was the Dominican Republic's first medal in the men's 400 metres. Lalonde Gordon's bronze was Trinidad and Tobago's first medal in the event since 1964.
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.
Anton Mikhailovich Chupkov is a Russian competitive swimmer. He is the European record holder in the long course 200 metre breaststroke and the Russian record holder in the long course 100 metre breaststroke. He formerly held the world record in the long course 200 metre breaststroke. At the 2015 European Games he won four gold medals in individual and relay events. He won the bronze medal in the 200 metre breaststroke at the 2016 Summer Olympics. He won the gold medal in the 200 metre breaststroke at the 2017 and 2019 World Aquatics Championships.
Evgeny Mikhailovich Rylov is a Russian competitive swimmer and Olympic champion specializing in backstroke events. He won three gold medals at the 2014 Summer Youth Olympics in Nanjing, and a bronze medal at his senior international debut at the 2015 World Championships in Kazan. He also won a bronze medal at the 2016 Summer Olympics in Rio de Janeiro and a gold medal at the 2017 World Championships in Budapest, both were in the 200 metre backstroke event. In 2018, at the 2018 World Short Course Championships, he won gold medals in the 200 metre backstroke and 50 metre backstroke. At the 2019 World Championships, he won a gold medal in the 200 metre backstroke, silver medal in the 100 metre backstroke, and silver medal in the 50 metre backstroke. He won the gold medal in the 100 metre backstroke and 200 metre backstroke at the 2020 Summer Olympics in Tokyo.
Cynthia Maduengele Bolingo Mbongo, known as Cynthia Bolingo, is a Belgian sprinter. In a career beset with injuries, she won the silver medal in the 400 metres at the 2019 European Athletics Indoor Championships and the bronze medal in the 4 x 400 metres at the 2024 European Athletics Championships.
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 women's 400 metres hurdles event at the 2020 Summer Olympics took place between 31 July and 4 August 2021 at the Japan National Stadium. 39 athletes from 25 nations competed.
The women's 200 metres at the 2019 World Athletics Championships was held at the Khalifa International Stadium in Doha, Qatar, from 30 September to 2 October 2019.
Femke Bol is a Dutch track and field athlete who competes in hurdling and sprinting. She specialises in the 400 metres hurdles, where she is the 2023 World Champion, and in the 400 metres, where she is the 2024 World Indoor Champion and the short track world record holder. In the 4 × 400 metres relay, she is the 2023 World Champion and the 2024 World Indoor Champion with the Dutch women's team and the 2024 Olympic Champion with the Dutch mixed team.
The women's 400 metres at the 2021 European Athletics Indoor Championships took place in three rounds at the Arena Toruń in Toruń, Poland, on 5 and 6 March 2021.
Alexander Doom is a Belgian sprinter specializing in the 400 metres. In 2024, he became the first male athlete to win the individual 400 metres and 4×400 metres relay at the same World Athletics Indoor Championships He has won several medals in international competitions with the Belgian 4 × 400 metres relay team and holds a personal best of 44.15 over the 400 metres.
Roos Vanotterdijk is a Belgian competitive swimmer. She is the Belgian record holder in the long course 50 metre freestyle, 100 metre freestyle, 50 metre backstroke, 100 metre backstroke, and 100 metre butterfly, as well as the short course 50 metre backstroke and 100 metre individual medley. She is a six-time medalist in individual events at the European Junior Swimming Championships and medalist at the European Youth Olympic Festival.
Helena Ponette is a Belgian sprinter specialising in the 400 metres. She competed at the 2024 Summer Olympics as a 400 metres runner and as a member of the Belgian women's 4x400 metres and mixed 4x400 metres relay teams. She also participated at multiple World and European Athletics championships, indoor and outdoor, individually and as a member of the 4x400 metres relay teams. She was national champion in the women's 400 metres in 2023.
The women's 400 metres at the 2022 European Athletics Championships took place in three rounds at the Olympiastadion in Munich, Germany, from 15 to 17 August 2022.
The women's 400 metres hurdles at the 2022 European Athletics Championships took place in three rounds at the Olympiastadion in Munich, Germany, from 17 to 19 August 2022.
The women's 400 metres at the 2023 European Athletics Indoor Championships took place in three rounds at the Ataköy Athletics Arena in Istanbul, Turkey, on 3 and 4 March 2023. This was the 37th time the women's 400 metres were contested at the European Athletics Indoor Championships. Athletes could qualify by the entry standard of 52.20 seconds indoor or 50.80 seconds outdoor, or by their position on the World Athletics Ranking for the event.
The women's 400 metres hurdles at the 2023 World Athletics Championships took place in three rounds at the National Athletics Centre in Budapest, Hungary from 21 to 24 August 2023. On 21 August, forty-one athletes of thirty nations participated in the five heats of round 1. On 22 August, twenty-four athletes competed in the three heats of the semifinals. On 24 August, eight athletes competed in the final, which was won by Femke Bol of the Netherlands in 51.70 seconds, ahead Shamier Little of the United States in 52.80 seconds and Rushell Clayton of Jamaica in 52.81 seconds.
The women's 400 metres at the 2024 World Athletics Indoor Championships took place in three rounds at the Commonwealth Arena in Glasgow, Scotland, United Kingdom, on 1 and 2 March 2024. It was contested by twenty-four athletes from nineteen different nations.
The women's 4 × 400 metres relay at the 2024 World Athletics Indoor Championships took place in two rounds at the Commonwealth Arena in Glasgow, Scotland, United Kingdom, on 3 March 2024. There was no entry standard for the qualification. Nine national teams competed in the event.
The women's 400 metres hurdles at the 2024 European Athletics Championships took place in three rounds at the Stadio Olimpico in Rome, Italy, from 9 to 11 June 2024. This was the sixteenth time that the women's 400 metres hurdles was contested at the European Athletics Championships. A total of 37 athletes qualified for the event by entry standard, ranking, or wild card. The startlists contained 35 athletes from 21 nations.
