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.
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.
Finland competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. Finnish athletes have competed at every Olympic Games since its debut in 1908. The Finnish Olympic Committee sent the nation's smallest ever team to the Games after the 1932 Summer Olympics in Los Angeles. A total of 53 athletes, 36 men and 17 women, competed only in 12 sports; the nation's team size was roughly denser from Sydney by a quarter of the athletes.
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.
Bulgaria competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's seventeenth appearance at the Summer Olympics, except for three occasions, including the 1984 Summer Olympics in Los Angeles, because of the Soviet boycott. The Bulgarian Olympic Committee sent 95 athletes, 49 men and 46 women, to compete in 19 sports. Shooting champion and four-time Olympian Mariya Grozdeva became the nation's first ever female flag bearer in the opening ceremony.
Israel competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. It was the nation's thirteenth appearance at the Summer Olympics.
Chile competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004.
Slovenia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's fourth consecutive appearance at the Summer Olympics since the post-Yugoslav era. The Slovenian Olympic Committee sent the nation's largest ever delegation to the Games in Olympic history. A total of 79 athletes, 56 men and 23 women, competed in 10 sports. For the second consecutive time, men's handball was the only team-based sport in which Slovenia had its representation at these Games.
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.
Peru competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's fifteenth appearance at the Olympics, except the 1952 Summer Olympics in Helsinki.
Mongolia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's tenth appearance at the Olympics, except the 1984 Summer Olympics in Los Angeles, because of its partial support to the Soviet boycott.
Slovakia 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 since the post-Czechoslovak era. The Slovak Olympic Committee sent a total of 64 athletes to the Games, 48 men and 16 women, to compete in 11 sports. There was only a single competitor in artistic and trampoline gymnastics and sailing.
Trinidad and Tobago competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's sixteenth appearance at the Summer Olympics as an independent nation, although it had previously appeared in four editions as part of the British colony and the West Indies Federation. Trinidad and Tobago Olympic Committee sent a total of nineteen athletes to the Games, ten men and nine women, to compete only in track and field, shooting, swimming, and taekwondo, which made its Olympic debut; the nation's team size was relatively similar to the record in Sydney four years earlier.
Barbados competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This nation marked its ninth appearance at the Olympics, except the 1980 Summer Olympics in Moscow because of the United States boycott.
Cyprus competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004.
Nicaragua competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004.
The United Arab Emirates competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's sixth consecutive appearance at the Olympics.
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.
Oman competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's eighth consecutive appearance at the Olympics.
Malta competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016. This was the nation's sixteenth appearance at the Summer Olympics, since its debut in 1928, although it failed to register any athletes in five other editions.
