Australia has sent athletes to all editions of the modern Olympic Games. Australia has competed in every Summer Olympic Games, as well as every Winter Olympics except 1924–32 and 1948. In 1908 and 1912 Australia competed with New Zealand under the name Australasia.
Hungary first participated at the Olympic Games at the inaugural 1896 Games, and has sent athletes to compete in most Summer Olympic Games and every Winter Olympic Games since then. The nation was not invited to the 1920 Games for its role in World War I, and was part of the Soviet-led boycott of the 1984 Summer Olympics.
The United Kingdom has been represented at every modern Olympic Games, and as of the 2020 Summer Olympics is third in the all-time Summer Olympic medal table by both number of gold medals won and overall number of medals. London has hosted the Summer Olympic Games three times: in 1908, 1948, and 2012.
Italy has sent athletes to most of the modern Olympic Games held since 1896, outside of not having "officially" participated in the 1904 Summer Olympics.
The modern Olympic Games were founded by French historian Pierre de Coubertin. France has competed in every edition, with the possible exception of the 1904 Games.
Norway first participated at the Summer Olympics in 1900, and has sent athletes to compete in every Games since then, except for the 1980 Summer Olympics in Moscow when they participated in the American-led boycott and, as previously thought, the 1904 Games in St. Louis, United States. However, at the beginning of the 21st century, it was discovered that wrestlers Charles Ericksen and Bernhoff Hansen, who were Norwegian expatriates in America whose medals at the 1904 Summer Olympics were previously attributed to United States, still held Norwegian citizenship at the time of the games. They won the gold medals in the wrestling welterweight and heavyweight events respectively.
Russia, officially known as the Russian Federation, has competed at the modern Olympic Games on many occasions, but as different nations in its history. As the Russian Empire, the nation first competed at the 1900 Games, and returned again in 1908 and 1912. After the Russian revolution in 1917, and the subsequent establishment of the Soviet Union in 1922, it would be thirty years until Russian athletes once again competed at the Olympics, as the Soviet Union at the 1952 Summer Olympics. After the dissolution of the Soviet Union in 1991, Russia competed as part of the Unified Team in 1992, and finally returned once again as Russia at the 1994 Winter Olympics.
Argentina participated at the Olympic Games for the first time in 1900. It has participated at all subsequent Summer Olympics except in 1904, 1912, and the nation boycotted the Moscow Olympics due to its support for the United States in 1980. It participated at the Winter Olympics in 1928, 1948, 1952 and continuously since 1960.
Cuba first participated at the Olympic Games in 1900, and has sent athletes to compete in 20 of 28 Summer Olympic Games overall.
Canada has competed at every Winter Olympic Games, and has won at least one medal each time. By total medals, the country's best performance was in the 2018 Winter Olympic Games where Canadian athletes won 29 medals. Canada set a new record for most gold medals won by a country in a single Winter Olympics with 14 at the 2010 Winter Olympics in Vancouver, Canada. This achievement surpassed the previous record of 13 gold medals held by the Soviet Union (1976) and Norway (2002). Both Germany and Norway matched the record total of 14 gold medals in Pyeongchang in 2018. This record has since been surpassed by Norway with 16 at the 2022 Winter Olympics.
Mexico first participated at the Olympic Games in 1900 and has sent athletes to compete in every Summer Olympic Games since 1924. Mexico has also participated in several Winter Olympic Games since 1928, though has never medaled in the Winter Olympics.
Brazil first participated at the Olympic Games in 1920, after missing the previous five Summer editions. The country has sent athletes to compete in every Summer Olympic Games since then, except for the 1928 Games. As of 2020, Brazilian athletes have won a total of 150 medals in 18 different Summer sports.
Indonesia first participated in the Olympic Games in 1952 and has sent athletes to compete in every Summer Olympic Games since then, except for 1964, due to controversy around the Games of the New Emerging Forces, and 1980, when they participated in the U.S.-led boycott of the 1980 Summer Olympics. Indonesia is yet to participate in the Winter Olympic Games. The nation's non-participation in the Winter Olympics is largely due to the lack of sports facilities for winter sports on its territory.
Nigeria first participated in the Olympic Games in 1952, and has sent athletes to compete in every Summer Olympic Games since then, except for the boycotted 1976 Summer Olympics. The nation participated in the Winter Olympic Games in 2018, having qualified female athletes in bobsleigh and skeleton.
Portugal first participated at the Olympic Games in 1912 and has since taken part in every edition of the Summer Olympic Games. Earlier that year, the Olympic Committee of Portugal was recognised by the International Olympic Committee as the Portuguese National Olympic Committee. In 1952, athletes representing Portugal competed for the first time at the Olympic Winter Games, and have only missed two editions since 1988.
The Philippines has competed in every edition of the Summer Olympic Games since its debut in the 1924 edition, except when they participated in the American-led boycott of the 1980 Summer Olympics. Filipino athletes have also competed at the Winter Olympic Games on five occasions since 1972.
Morocco first participated at the Olympic Games in 1960, and has sent athletes to compete in every Summer Olympic Games since then, except when they participated in the American-led boycott of the 1980 Summer Olympics. Morocco also boycotted the 1976 Games, withdrawing after having initially sent a delegation. In doing so, Morocco joined the boycott of the Games by most African countries, in protest against New Zealand's participation following an All Blacks rugby match, unrelated to the Olympics, against an apartheid team from South Africa. Only one Moroccan representative had time to compete before his country's withdrawal: Abderahim Najim took part in the Men's Light Flyweight event in boxing, and lost his first and only match.
Malaysia first participated at the Olympic Games in 1956, and has sent athletes to compete in every Summer Olympic Games since then, except when Malaysia participated in the American-led boycott of the 1980 Summer Olympics. Malaysia made their debut at the Winter Olympic Games in 2018.
People's Republic of China first competed at the Paralympic Games in 1984, at the Summer Games in New York City, United States and Stoke Mandeville, United Kingdom. Since the 2004 Summer Paralympics, China has topped the medal table with more gold medals, more silver medals and more medals overall than any other nation at every Summer Paralympics.
The United States of America has sent athletes to every celebration of the Winter Olympic Games. The United States Olympic & Paralympic Committee (USOPC) is the National Olympic Committee for the United States.
