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.
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.
Russia 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 as an independent nation. The Russian Olympic Committee sent a total of 446 athletes to the Games, 244 men and 202 women, to compete in all sports, except baseball, field hockey, football, and softball.
Hungary competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. Hungarian athletes have competed at every Summer Olympic Games in the modern era, except the 1920 Summer Olympics in Antwerp, and the 1984 Summer Olympics in Los Angeles because of the Soviet boycott. The Hungarian Olympic Committee sent a total of 209 athletes to the Games, 119 men and 90 women, to compete in 20 sports. Water polo and handball were the only team-based sports in which Hungary had its representation in these Olympic Games. There was only a single competitor in road cycling and mountain biking.
Serbia and Montenegro competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. Previously known as the Federal Republic of Yugoslavia, this was the nation's third and last joint appearance at the Summer Olympics before Serbia and Montenegro became separated independent states in 2006. The Olympic Committee of Serbia and Montenegro sent a total of 85 athletes to the Games, 78 men and 7 women, to compete in 14 sports. Men's basketball, football, volleyball, and water polo were the only team-based sports in which Serbia and Montenegro had its representation at these Games. There was only a single competitor in road cycling, judo, tennis, and wrestling.
Croatia 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 Croatian Olympic Committee sent the nation's smallest delegation to the Games since its debut in 1992. A total of 81 athletes, 66 men and 15 women, competed in 14 sports. Men's water polo, and men's handball were the only team-based sports in which Croatia had its representation in these Olympic Games.
The People's Republic of China, the previous host of the 2008 Olympics at Beijing, competed at the 2012 Summer Olympics in London, the United Kingdom, between 27 July and 12 August 2012. This was the nation's ninth appearance at the Summer Olympics since its debut in 1952. A total of 396 Chinese athletes, 171 men and 225 women, were selected by the Chinese Olympic Committee to compete in 23 sports. For the fourth time in its Olympic history, China was represented by more female than male athletes.
Italy 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, except for the 1904 Summer Olympics in St. Louis. The Italian National Olympic Committee sent the nation's smallest delegation to the Games since the 1988 Summer Olympics in Seoul. A total of 285 athletes, 162 men and 123 women, competed in 22 sports.
Hungary competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. Hungarian athletes have competed at every Summer Olympic Games in the modern era, except the 1920 Summer Olympics in Antwerp, and the 1984 Summer Olympics in Los Angeles because of the Soviet boycott. The Hungarian Olympic Committee sent the nation's smallest delegation to the Games since 1956 to London. A total of 159 athletes, 97 men and 62 women, competed in 18 sports.
Serbia competed at the 2012 Summer Olympics in London. This was the nation's third appearance at the Summer Olympics.
Croatia competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's sixth consecutive appearance at the Summer Olympics.
Greece competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. The Hellenic Olympic Committee sent a total of 103 athletes to the Games in London, 65 men and 38 women, to compete in 19 sports. Men's water polo was the only team event in which Greece was represented at these Olympic Games.
Montenegro competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's second appearance at the Summer Olympics.
The United States competed at the 2011 Pan American Games in Guadalajara, Mexico, from October 14 to October 30, 2011.
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.
Croatia 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. The Croatian Olympic Committee confirmed a roster of 87 athletes, 68 men and 19 women, to compete across 18 sports at the Games.
Water polo competitions at the 2015 Pan American Games in Toronto was held from July 7 to 15 at the Markham Pan Am Centre in Markham. The water polo competitions was the first sporting event to be conducted at the games, beginning three days before the opening ceremony. This is because the Pan American Games were scheduled to be held roughly around the same time as the 2015 World Aquatics Championships scheduled for Kazan, Russia, thus the competition was moved forward to allow for a sufficient gap between the two events. A total of eight men's and women's teams competed in each respective tournament.
Water polo competitions at the 2019 Pan American Games in Lima, Peru were held from July 28 to August 10. The venue for the competition was the water polo pool located at the Villa María del Triunfo cluster. A total of eight men's and eight women's teams competed in each tournament. This meant a total of 176 athletes were scheduled to compete.
Water polo competitions at the 2022 South American Games in Asunción, Paraguay were held from 11 to 15 October 2022 at the Centro Acuático Nacional cluster.
Water polo competitions at the 2023 Pan American Games was held from October 30 to November 4. The venue for the competition was the Aquatic Center, in Santiago, Chile. A total of eight men's and eight women's teams competed in each tournament. This means a total of 192 athletes competed.
