Australia, the previous host of the 2000 Olympics at Sydney, 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.
Italy competed at the 2004 Summer Olympics in Athens, Greece, from the 13th to the 29th of August 2004. The country has competed at every Summer Olympic games in the modern era, except for the 1904 Summer Olympics in St. Louis. The Italian National Olympic Committee sent the nation's largest ever delegation in history to the Games. A total of 364 athletes, 229 men and 135 women, competed in 27 sports.
China competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's ninth appearance at the Summer Olympics since its debut in 1952. A total of 384 Chinese athletes, 136 men and 248 women, were selected by the Chinese Olympic Committee to compete in 28 sports. For the third time in its Olympic history, China was represented by more female than male athletes.
Argentina competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's twenty-first appearance at the Olympic Games, except for three different editions. Argentina did not attend the 1904 Summer Olympics in St. Louis, the 1912 Summer Olympics in Stockholm, and the 1980 Summer Olympics in Moscow, because of its support for the United States-led boycott. The sailor Carlos Espínola was the nation's flag bearer at the opening ceremony. 152 competitors, 106 men and 46 women, took part in 86 events in 22 sports.
Serbia competed at the 2008 Summer Olympics in Beijing, People's Republic of China. The country returned under the name Serbia after 96 years, previously competing under the names Yugoslavia (1920–1988), Independent Olympic Participants (1992), Yugoslavia (1996–2002) and Serbia and Montenegro (2004–2006).
Belgium competed at the 2008 Summer Olympics in Beijing, People's Republic of China. 96 Belgians took part in Beijing, the biggest delegation for the country since 1976. Belgium won 2 gold medals, better achievement than in 2004, when the country won 1 gold and 2 bronze medals.
Japan competed at the 2008 Summer Olympics in Beijing, People's Republic of China. The delegation of athletes and officials were represented by the Japanese Olympic Committee.
Germany competed at the 2008 Summer Olympics in Beijing, People's Republic of China. A total of 439 athletes were nominated to participate in the Games. The German Olympic Sports Confederation nominated athletes on 29 May, 23 June and 15 July 2008. Reaching the qualification standard set by the relevant sport's international governing body did not automatically mean that the athlete was nominated for Beijing, as the DOSB had stricter qualification standards. An athlete needed to have a somewhat realistic chance for a top 12 position. An exception to this are the team events, as the number of competing teams is already very limited through the IOC standards, and a chance for a respective place is already given by the qualification.
Croatia competed at the 2008 Summer Olympics in Beijing, People's Republic of China.
Brazil sent a delegation to compete at the 2008 Summer Olympics in Beijing, China, in August 2008. Brazilian athletes have competed in every Summer Olympic Games since 1920, except the 1928 Summer Olympics. The country is represented by the Brazilian Olympic Committee. Brazil headed to the Beijing Games with its largest Olympic delegation at the time, 277 athletes, including 132 women.
China was the host nation of the 2008 Summer Olympics. It was represented by the Chinese Olympic Committee (COC), and the team of selected athletes were officially known as Team China.
Sweden sent a team to compete at the 2008 Summer Olympics in Beijing, People's Republic of China.
New Zealand took part in the 2008 Summer Olympics in Beijing, China. The country sent 182 competitors, making this its largest ever delegation to the Olympic Games. It was also one of the most successful, equalling New Zealand's combined medal tally from the previous two Summer games. On 16 August – dubbed "Super Saturday" by journalists – New Zealand had its greatest single day at any Olympics, winning 5 medals: two gold, one silver and two bronze. New Zealand also gained its first Olympic track medal since 1976 when Nick Willis won the silver medal in the men's 1500 metres, becoming the sixth New Zealander to win an Olympic medal in that event. The success at the Olympics has boosted Athletics participation since then.
South Korea competed at the 2008 Summer Olympics in Beijing, China. This is a list of all of the South Korean athletes who qualified for the Olympics and their results. South Korea sent a delegation of 267 athletes to these games.
Norway competed at the 2008 Summer Olympics in Beijing, People's Republic of China.
The Russian Federation competed at the 2008 Summer Olympics, held in Beijing, China, represented by the Russian Olympic Committee. Russia competed in all sports except baseball, field hockey, football, softball, and taekwondo. It ranked third in the medal table by the number of gold (24) and overall (60) medals. Russia also had 14 medals stripped for doping violations, the most of any nation at the 2008 Olympics, although in terms of gold medals it got a net positive of +1.
Poland competed at the Beijing 2008 Summer Olympics. The country's delegation included 268 athletes.
Argentina competed at the 2008 Summer Olympics held in Beijing, China, from 8 to 24 August 2008. 137 athletes qualified for the Olympic Games in 19 sports. Manu Ginóbili, basketball player and gold medalist at the 2004 Summer Olympics, was the nation's flag bearer at the opening ceremony.
Honduras sent a delegation to compete at the 2008 Summer Olympics in Beijing, China.
The United States of America (USA) competed at the 2004 Summer Olympics in Athens, Greece. 533 competitors, 279 men and 254 women, took part in 254 events in 31 sports.
