Togo competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. The country's participation at Athens marked its seventh appearance in the Summer Olympics since its debut at the 1972 Summer Games in Munich, West Germany. The delegation included two track and field athletes and a single canoeist; Jan Sekpona in the men's 800 metres, Sandrine Thiébaud-Kangni in the women's 400 metres, and Benjamin Boukpeti in the men's K-1. Both Sekpona and Thiébaud-Kangni were eliminated in the first round of their competitions, while Boukpeti progressed to the semi-finals.
Sunday Bada was a Nigerian sprinter who specialized in the 400 metres event. He won three medals at the World Indoor Championships, including a gold medal in 1997. His personal best time was 44.63 seconds, and with 45.51 seconds indoor he holds the African indoor record. He set a national record in the 4 x 400 metres relay at the 2000 Olympics, where the Nigerian team also won gold medals after the disqualification of the US team who had finished first.
Martyn Joseph Rooney is an English sprinter who specialises in the 400 metres event. He reached the 400 m final at the 2008 Summer Olympics and won bronze in the 4×400 metres relay. A mainstay on the anchor leg of the Great Britain and England 4 x 400 metre relay teams, at the 2009 World Championships in Athletics he won a silver medal with the Great Britain relay team, and bronze in the 2015 and 2017 World Championships.
The Maldives competed at the 1996 Summer Olympics in Atlanta, United States, from 19 July to 4 August 1996. The delegation's participation in the Atlanta Olympics marked the Maldives' third appearance at the Summer Olympics since their debut at the 1988 Summer Olympics in Seoul, South Korea. Six athletes competed across two sports; Mohamed Amir, Naseer Ismail, Hussain Riyaz, Ahmed Shageef and Yaznee Nasheeda in track and field, and Moosa Nazim in swimming. None of the track or swimming athletes advanced past the first round in their events, and no Maldivian has won a medal in any events. Ahmed Shageef bore the Maldives' flag during the parade of nations of the opening ceremony.
Saint Kitts and Nevis first participated at the Olympic Games in 1996, and have competed in every Summer Olympic Games since then. The country has not competed at the Winter Olympic Games.
Rabah Mahhamed Yousif Bkheit is a Sudanese-born British track and field athlete, who initially competed for Sudan before obtaining British citizenship.
Fabio Francesco Grossi is a retired Italian sprinter who specialized in the 400 metres.
Michael Walter Mathieu is a retired Bahamian sprinter hailing 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.
Yousef Ahmed Masrahi is a Saudi Arabian track and field athlete, who specialises in the 400 metres sprint. His personal best time for the event is 43.93 seconds, set in 2015, and is the Asian record.
Luguelín Miguel Santos Aquino is a Dominican sprinter, who specialises in the 400 m. He was the silver medallist in the event at the 2012 London Olympics at the age of nineteen. His personal best is 44.11 seconds.
Liemarvin Bonevacia is a Dutch sprinter specialising in the 400 metres. He won bronze medals in the event at the 2016 and 2024 European Athletics Championships, and the 2017 and 2021 European Indoor Championships. Bonevacia also earned five major medals for the 4 × 400 m relays, either men's or mixed, including silver medal in the men's relay at the 2020 Tokyo Olympics.
Mahau Camargo Suguimati is a Brazilian track hurdler of Japanese ancestry. Since the age of eight, Suguimati had lived and studied for sixteen years in Niiza, Japan. Suguimati also attended schools around the prefecture, where he discovered his natural ability and talent of running and hurdling, under his personal coach and trainer Atsushi Hishinuma. He made his international debut, and represented his birth nation Brazil at the 2007 Pan American Games in Rio de Janeiro, where he finished seventh in the final of the 400 m hurdles, with his personal best time of 49.63 seconds.
Dimitrios Gravalos is a Greek sprinter, who specialized in the 400 metres. He won the gold medal for the 400 metres at the 2003 European Junior Championships in Tampere, Finland, with a time of 46.54 seconds.
Pantelis Melachroinoudis is a Greek sprinter, who specialized in the 400 metres. Melachroinoudis competed for the men's 4 × 400 m relay at the 2008 Summer Olympics in Beijing, along with his teammates Stylianos Dimotsios, Konstadinos Anastasiou, and Dimitrios Gravalos. He ran on the third leg of the second heat, with an individual-split time of 45.15 seconds. Melachroinoudis and his team finished the relay in seventh place for a seasonal best time of 3:04.30, failing to advance into the final.
Yoel Armando Tapia Gómez is a Dominican sprinter, who specialized in the 400 metres. He won two medals for the national relay team at the 2007 Pan American Games in Rio de Janeiro, Brazil, and also, at the 2011 Pan American Games in Guadalajara, Mexico.
Brice Panel is a French sprinter, who specialized in the 400 metres. He set his personal best time of 45.54 seconds by finishing second at the Resisprint meeting in La Chaux-de-Fonds.
Jovon Toppin is a Trinidadian sprinter, who specialized in the 400 metres. Toppin competed for the men's 4 × 400 m relay at the 2008 Summer Olympics in Beijing, along with his teammates Ato Modibo, Cowin Mills, and Stann Waithe. He ran on the second leg of the second heat, with an individual-split time of 45.92 seconds. Toppin and his team finished the relay in fifth place, for a seasonal best time of 3:04.12, failing to advance into the final.
Carl Oliver Jr. is a Bahamian former track and field sprinter who specialised in the 400 metres. He is the current secretary of the Bahamas Association of Athletic Associations. His greatest achievements on the track came with the Bahamian 4×400 metres relay team. He was a bronze medallist in the relay at the 2000 Summer Olympics and was also a finalist at the 1996 Atlanta Olympics and the 1999 World Championships in Athletics. He helped set a national record of 3:02.85 minutes at the 1995 World Championships in Athletics.
Wayde van Niekerk is a South African track and field sprinter who competes in the 200 and 400 metres. In the 400 metres, he is the current world and Olympic record holder, having set the record when he won the event at the 2016 Olympics.
Matthew Hudson-Smith is a British track and field sprinter who specialises in the 400 metres and is the 5th fastest athlete of all-time over the distance. As of September 2024 he is ranked as the number one 400m runner in the world and has won six British titles, five Diamond League events, two individual European titles, an individual Olympic silver medal, World Championships silver and bronze individual medals and an individual Commonwealth silver medal. He has also won a number of relay titles including an Olympic bronze medal, World Championships bronze medal, two European gold medals, one European silver medal, one European bronze medal and a Commonwealth Games gold medal. Hudson-Smith also holds the European and British 4x400m records (2:55.83) along with the GB Team who ran in the final of the men's 4x400m event in the Paris 2024 Olympics.
South Africa 
