Puerto Rico competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's fifteenth consecutive appearance at the Olympics.
Kazakhstan competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's third appearance at the Summer Olympics in the post-Soviet era.
Ukraine competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's third consecutive appearance at the Summer Olympics in the post-Soviet era. The National Olympic Committee of Ukraine sent the nation's largest ever delegation to these Games. A total of 240 athletes, 125 men and 115 women, took part in 21 sports. Women's handball was the only team-based sport in which Ukraine had its representation at these Games for the first time. There was only a single competitor in modern pentathlon and taekwondo.
India competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. The Indian Olympic Association sent a total of 73 athletes, 48 men, and 28 women, to compete in 14 sports. Men's field hockey was the only team-based sport in which India had its representation in these Olympic games. As a pleasant surprise, the shooting team came successful with a silver medal, the winner being Capt. Rajyavardhan Singh Rathore. He was the first Indian to win an individual silver medal.
Mexico competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's twentieth appearance at the Olympics, since its debut in 1900. Comité Olímpico Mexicano sent the nation's largest delegation to the Games since 1992. A total of 109 athletes, 59 men and 50 women, competed in 20 sports. Football was the only team-based sport in which Mexico had its representation in these Olympic Games. There was only a single competitor in fencing, shooting, and weightlifting.
Belarus competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's fifth appearance at the Summer Olympics in the post-Soviet era. The Belarus Olympic Committee sent a total of 151 athletes to the Games, 82 men and 69 women, to compete in 22 sports.
Poland competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eighteenth appearance at the Summer Olympics, except the 1984 Summer Olympics in Los Angeles, because of the Soviet boycott. The Polish Olympic Committee sent a total of 194 athletes to the Games, 132 men and 62 women, to compete in 21 sports. Men's volleyball was the only team-based sport in which Poland had its representation in these Olympic Games. There was only a single competitor in women's taekwondo.
Czech Republic competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's third appearance at the Summer Olympics after gaining its independence from the former Czechoslovakia. The Czech Olympic Committee sent the nation's largest team to the Games since the post-Czechoslovak era. A total of 142 athletes, 80 men and 62 women, competed in 19 sports; the nation's team size was roughly denser from Sydney by one sixth of the athletes. Women's basketball was the only team-based sport in which the Czech Republic had its representation at these Olympic Games. There was only a single competitor in equestrian, artistic and trampoline gymnastics, judo, and weightlifting.
Norway competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's twenty-fourth appearance at the Summer Olympics, except for the 1904 Summer Olympics in St. Louis, and the 1980 Summer Olympics in Moscow, due to the country's support of the United States boycott. With the absence of women's football and handball teams, Norwegian Olympic and Paralympic Committee and Confederation of Sports sent the nation's smallest delegation to the Games since the 1968 Summer Olympics in Mexico City. A total of 53 athletes, 36 men and 17 women, competed only in 12 different sports. There was only a single competitor in badminton, swimming, taekwondo, weightlifting, and wrestling.
Thailand competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's thirteenth appearance at the Olympics, except the 1980 Summer Olympics in Moscow because of its partial support to the United States boycott.
Iran competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. The nation has competed at every Summer Olympic games, since its official debut in 1948 with the exception of the 1980 and 1984 Summer Olympics. The National Olympic Committee of the Islamic Republic of Iran sent a total of 38 athletes, 37 men and 1 woman, to compete in 10 sports. Half-lightweight judoka Arash Miresmaeili, who later forfeited his first match against Israel's Ehud Vaks for medical reasons, was the nation's flag bearer in the opening ceremony.
Colombia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's sixteenth appearance at the Olympics, except the 1952 Summer Olympics in Helsinki.
Latvia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eighth appearance at the Summer Olympics.
Kyrgyzstan competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's third appearance at the Olympics in the post-Soviet era.
Tunisia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eleventh appearance at the Olympics, except the 1980 Summer Olympics in Moscow because of its partial support to the United States boycott.
Uzbekistan competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's third consecutive appearance at the Olympics. The National Olympic Committee of the Republic of Uzbekistan sent a total of 70 athletes to the Games, 52 men and 18 women, to compete in 13 different sports, tying its delegation record with Sydney four years earlier. There was only a single competitor in road cycling, artistic and trampoline gymnastics, and table tennis.
Morocco competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eleventh appearance at the Olympics, except the 1980 Summer Olympics in Moscow, because of its partial support to the United States boycott.
Moldova competed at the 2004 Summer Olympics in Athens, from 13 to 29 August 2004. This was the nation's third consecutive appearance at the Summer Olympics in the post-Soviet era.
North Korea competed as the Democratic People's Republic of Korea at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's seventh appearance at the Olympics since its debut in 1972. North Korean athletes did not attend the 1984 Summer Olympics in Los Angeles, when they joined the Soviet boycott, and subsequently, led a boycott at the 1988 Summer Olympics in Seoul, along with six other nations.
Turkey competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This nation has competed at every Summer Olympic Games in the modern era since its debut in 1908. Turkey, however, did not attend the 1920 Summer Olympics in Antwerp, the 1932 Summer Olympics in Los Angeles at the period of worldwide Great Depression, and the 1980 Summer Olympics in Moscow because of its support for the United States boycott. The Turkish Olympic Committee sent the nation's largest delegation to the Games. A total of 114 athletes, 48 men and 66 women, competed in 16 sports. For the first time in its Olympic history, Turkey was represented by more female than male athletes. Women's basketball and women's volleyball were the only team-based sports in which Turkey had its representation in these Olympic games. There was only a single competitor in archery, badminton, and artistic gymnastics.
