Canada competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. Canadian athletes have competed in every Summer Olympic Games since 1900, except the 1980 Summer Olympics in Moscow because of the country's support for the US-led boycott.
Australia competed at the 2004 Summer Olympics in Athens, Greece from 13 to 29 August 2004. Australian athletes have competed in every Summer Olympic Games of the modern era. The Australian Olympic Committee sent a total of 470 athletes to the Games to compete in 29 sports.
Great Britain, the team of the British Olympic Association (BOA), competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004 with the team of selected athletes was officially known as Team GB. The British sent a wide-ranging delegation to the Games, continuing its ubiquitous presence in the Olympic games, the only country to have sent competitors to every summer and winter games since the birth of the modern Olympics in 1896. Great Britain's 264 athletes, 161 men and 103 women, competed in 22 disciplines throughout the two-week event. The team entered the opening ceremony behind the Union Flag carried by judoka Kate Howey. Double gold medal winner Kelly Holmes carried the flag at the closing ceremony.
The men's team pursuit event in cycling at the 2004 Summer Olympics consisted of matches between two teams of four cyclists. The teams started at opposite ends of the track. They had 16 laps in which to catch the other cyclist. If neither was caught before one had gone 16 laps, the times for the distance were used to determine the victor. The Australia-Great Britain rivalry continued in an event which saw a new world record.
The Czech Republic competed at the 2000 Summer Olympics in Sydney, Australia.
Ukraine competed at the 2000 Summer Olympics in Sydney, Australia. 230 competitors, 139 men and 91 women, took part in 185 events in 23 sports.
Slovakia competed at the 2000 Summer Olympics in Sydney, Australia.
Greece competed at the 2008 Summer Olympics in Beijing, People's Republic of China. They were represented by the Hellenic Olympic Committee, which announced on July 28, 2008, the 156 Greek athletes to compete in Beijing, composed of 84 men and 72 women, the largest Greek Olympic team ever excluding the home team of the Athens 2004 Olympics. Greece took part in archery, athletics, basketball, boxing, canoeing, cycling, diving, gymnastics, judo, rowing, sailing, shooting, swimming, synchronized swimming, table tennis, taekwondo, tennis, triathlon, beach volleyball, water polo, weightlifting and wrestling.
The men's sprint at the 2008 Summer Olympics took place on August 17–19 at the Laoshan Velodrome. There were 21 competitors from 15 nations, with each nation limited to two cyclists. The event was won by Chris Hoy of Great Britain, the nation's first victory in the men's sprint and first medal in the event since 1948. He faced his teammate Jason Kenny in the final, the first time since 1984 that one nation had taken the top two spots. Mickaël Bourgain of France earned bronze. Germany's four-Games podium streak ended.
The men's team sprint event in cycling at the 2000 Summer Olympics was contested by twelve teams. The races were held on Sunday, 17 September at the Dunc Gray Velodrome.
The United States competed at the 2004 Summer Olympics in Athens, Greece. 533 competitors, 279 men and 254 women, took part in 254 events in 31 sports.
The United States competed at the 2000 Summer Olympics in Sydney, Australia. 586 competitors, 333 men and 253 women, took part in 265 events in 31 sports.
Great Britain, or in full Great Britain and Northern Ireland, represented by the British Olympic Association (BOA), competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016 and the team of selected athletes was officially known as Team GB. British athletes have appeared in every Summer Olympic Games of the modern era, alongside Australia, France, Greece, and Switzerland, though Great Britain is the only country to have won at least one gold medal at all of them. The team represented the United Kingdom, the three Crown Dependencies, and the thirteen British Overseas Territories, ten of whom sent representatives.
Slovenia competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016. This was the nation's seventh consecutive appearance at the Summer Olympics as an independent nation.
Portugal competed at the 2020 Summer Olympics in Tokyo, from 23 July to 8 August 2021. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed because of the COVID-19 pandemic. Portuguese athletes have appeared in every edition of the Summer Olympic Games since the nation's debut in 1912.
Lithuania competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021, because of the COVID-19 pandemic. It was the nation's eighth consecutive appearance at the Games in the post-Soviet era and tenth overall in Summer Olympic history.
Ukraine competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021, due to the worldwide COVID-19 pandemic. It was the nation's seventh consecutive appearance at the Summer Olympics in the post-Soviet era with its smallest representation ever.
Thailand competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021, because of the COVID-19 pandemic. Since the nation's official debut in 1952, Thai athletes have appeared in every edition of the Summer Olympic Games, with the exception of the 1980 Summer Olympics in Moscow, because of its partial support of the US-led boycott.
Trinidad and Tobago competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021, due to the COVID-19 pandemic. It was the nation's eighteenth appearance at the Summer Olympics, although it previously competed in four other editions as a British colony, and as part of the West Indies Federation.
The men's team sprint event at the 2020 Summer Olympics took place on 3 August 2021 at the Izu Velodrome. 24 cyclists from 8 nations competed.
