Japan competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. Japanese athletes have competed at every Summer Olympic Games in the modern era since 1912 except for two editions; it was not invited to the 1948 Summer Olympics in London for its role in World War II, and was also part of the US-led boycott of the 1980 Summer Olympics in Moscow. The Japanese Olympic Committee sent a total of 306 athletes, 139 men and 167 women, to compete in 27 sports. For the first time in its Olympic history, Japan was represented by more female than male athletes.
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.
Sweden competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This nation has competed at every Summer Olympic Games in the modern era, except for the 1904 Summer Olympics in St. Louis. The Swedish Olympic Committee sent the nation's smallest team to the Games since the 1976 Summer Olympics in Montreal. A total of 115 athletes, 62 men and 53 women, competed only in 20 different sports. Women's football was the only team-based sport in which Sweden had its representation at these Games. There was only a single competitor in boxing, diving, artistic gymnastics, judo, modern pentathlon, and rowing.
Italy competed at the 1980 Summer Olympics in Moscow, Russian SFSR, USSR. In partial support of the American-led boycott of the 1980 Summer Olympics, Italy competed under the Olympic Flag instead of its national flag. 159 competitors, 121 men and 38 women, took part in 88 events in 19 sports.
Athletes from the Socialist Federal Republic of Yugoslavia competed at the 1980 Summer Olympics in Moscow, USSR. 164 competitors, 135 men and 28 women, took part in 69 events in 17 sports.
The People's Republic of China competed at the 1984 Summer Olympics in Los Angeles, United States. It was the first appearance at the Summer Games for the country after its mostly symbolic presence at the Summer Games in 1952 during which the dispute between the Republic of China and the PRC resulted in the former withdrawing all its athletes. After 1952 and until these games, the PRC boycotted the Olympics due to the Taiwan's presence as the Republic of China. In 1984, the Republic of China competed as Chinese Taipei and the PRC competed as China. Due to the then ongoing Sino-Soviet split, China did not participate in the Soviet-led boycott. In the previous games, China participated the United States-led boycott to protest the Soviet invasion of Afghanistan in 1979.
Switzerland competed at the 2000 Summer Olympics in Sydney, Australia. 102 competitors, 64 men and 38 women, took part in 82 events in 19 sports.
Australia was the host nation for the 2000 Summer Olympics in Sydney. Australian athletes have competed in every Summer Olympic Games. 617 competitors, 341 men and 276 women, took part in 270 events in 34 sports.
Japan competed at the 2000 Summer Olympics in Sydney, Australia. 266 competitors, 156 men and 110 women, took part in 156 events in 28 sports.
Hungary competed at the 2000 Summer Olympics in Sydney, Australia. 178 competitors, 109 men and 69 women, took part in 137 events in 23 sports.
Spain competed at the 2000 Summer Olympics in Sydney, Australia. 321 competitors, 216 men and 105 women, took part in 165 events in 27 sports.
Canada competed at the 2000 Summer Olympics in Sydney, Australia, held from 15 September to 1 October 2000. 294 competitors, 150 men, and 144 women, took part in 175 events in 29 sports.
The Unified Team at the 1992 Summer Olympics in Barcelona, Spain, was a joint team consisting of twelve of the fifteen former Soviet republics that chose to compete together; the states of Estonia, Latvia, and Lithuania competed separately. The team has been informally called the Commonwealth of Independent States team, though Georgia was not yet a member of the CIS when it competed as part of the Unified Team. Selected athletes from the Baltic states also competed on the Unified Team. It competed under the IOC country code EUN. A total of 475 competitors, 310 men and 165 women, took part in 234 events in 27 sports.
Kazakhstan competed in the Summer Olympic Games as an independent nation for the first time at the 1996 Summer Olympics in Atlanta, United States. Previously, Kazakhstani athletes competed for the Unified Team at the 1992 Summer Olympics. 96 competitors, 72 men and 24 women, took part in 99 events in 14 sports.
Turkey competed at the 2000 Summer Olympics in Sydney, Australia.
The Republic of China competed as Chinese Taipei at the 2000 Summer Olympics (中華臺北隊) in Sydney, Australia. The change in name was due to the political status of Taiwan. In addition, they flew a flag especially designed for the games separate from the flag of the Republic of China.
Athletes from East Germany competed at the 1972 Summer Olympics in Munich, West Germany. 297 competitors, 231 men and 66 women, took part in 161 events in 18 sports.
Athletes from East Germany competed at the 1980 Summer Olympics in Moscow, USSR. 346 competitors, 222 men and 124 women, took part in 167 events in 17 sports.
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.
The United States of America (USA), the previous host of the 1996 Olympics at Atlanta, competed at the 2000 Summer Olympics in Sydney, Australia. 586 competitors, 333 men and 253 women, took part in 265 events in 31 sports.
