Czech Republic competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's fifth appearance at the Summer Olympics after gaining its independence from the former Czechoslovakia. The Czech Olympic Committee sent a total of 133 athletes to the Games, 68 men and 65 women, to compete in 19 sports.
Finland competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. The nation has competed at every Summer Olympic Games since its official debut in 1908. The Finnish Olympic Committee sent a total of 56 athletes to the Games, 29 men and 27 women, to compete in 14 sports. There was only a single competitor in artistic gymnastics, taekwondo, weightlifting and tennis.
Latvia competed at the 2012 Summer Olympics in London, United Kingdom from July 27 to August 12, 2012. This was the nation's tenth appearance at the Summer Olympics.
Kazakhstan competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's fifth appearance at the Summer Olympics in the post-Soviet era.
Austria competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. The nation has competed at every edition of Summer Olympic Games, except the 1920 Summer Olympics in Antwerp. The Österreichisches Olympisches Comité sent a total of 70 athletes to the Games, 39 men and 31 women, to compete in 17 sports. This was approximately the same size as the previous Games, with the difference of one male athlete, the addition of one female athlete and three sporting events participated in. There was only a single competitor in eventing, fencing, rhythmic gymnastics, modern pentathlon, and Greco-Roman wrestling.
Bulgaria competed at the 2012 Summer Olympics in London, United Kingdom from 27 July to 12 August 2012. It was the nation's nineteenth appearance at the Summer Olympics, having missed the Olympics on three occasions, including the 1984 Summer Olympics in Los Angeles because of the Soviet boycott. Despite this being London's third Olympic Games, this was the first time a Bulgarian team appeared at a London Olympics. The Bulgarian Olympic Committee sent the nation's smallest delegation to the Games, tying the record with Helsinki in 1952, and with Tokyo in 1964. A total of 63 athletes, 36 men and 27 women, competed in 16 sports. Men's volleyball was the only team event in which Bulgaria was represented in these Olympic games. There was only a single competitor in badminton, sprint canoeing, fencing, and judo.
Slovakia competed in the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's fifth consecutive appearance at the Summer Olympics. The Slovak Olympic Committee sent a total of 47 athletes to the Games, 26 men and 21 women, to compete in 11 sports. There was only a single competitor in badminton, judo, triathlon, and weightlifting.
Chile competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This nation has competed at every Olympic games, except the 1932 Summer Olympics in Los Angeles, and the 1980 Summer Olympics in Moscow because of the United States boycott.
Cuba competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's nineteenth appearance in the Olympics. With baseball's removal from the Olympic program and the absence of the nation's volleyball team for the first time, the Cuban Olympic Committee sent the nation's smallest delegation to the Games since 1964. A total of 111 athletes, 66 men and 45 women, competed in 13 sports. There was only a single competitor in archery and table tennis.
Thailand competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's fifteenth appearance at the Olympics, except the 1980 Summer Olympics in Moscow because of its partial support to the United States boycott.
Chinese Taipei competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. "Chinese Taipei" was the designated name used by Taiwan to participate in some international organizations and almost all sporting events, including the Olympic Games. Neither the common name "Taiwan" nor the official name "Republic of China" would be used due primarily to opposition from the People's Republic of China. This was the nation's eighth consecutive appearance at the 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.
Slovenia competed at the 2012 Summer Olympics in London, United Kingdom. This was the nation's sixth consecutive appearance at the Summer Olympics. The Slovenian Olympic Committee sent the nation's third-largest delegation ever to the Games. A total of 65 athletes, 28 men and 37 women, competed in 15 sports. For the first time in its Olympic history, Slovenia was represented by more female than male athletes. Slalom kayaker and multiple-time world champion Peter Kauzer was the nation's flagbearer at the opening ceremony. The London Games also featured Slovenia's Olympic debut in triathlon.
Algeria competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's twelfth consecutive appearance at the Summer Olympics, except for the 1976 Summer Olympics in Montreal because of the African boycott.
Kenya competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's thirteenth appearance at the Olympics, they did not participate in the 1976 Summer Olympics in Montreal and the 1980 Summer Olympics in Moscow because of the African and United States boycott.
Benin competed at the 2012 Summer Olympics in London, United Kingdom from 27 July to 12 August 2012. This was the nation's tenth appearance at the Olympics, except the 1976 Summer Olympics in Montreal because of the African boycott.
Mozambique competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's ninth consecutive appearance at the Olympics. In the weeks before the Games, Mozambique athletes trained at Comberton Village College in Cambridge.
Kyrgyzstan competed at the 2012 Summer Olympics in London, United Kingdom from 27 July 2012 to 12 August 2012. This was the nation's fifth appearance at the Olympics in the post-Soviet era.
American Samoa competed at the 2012 Summer Olympics in London, United Kingdom from July 27 to August 12, 2012. This nation marked its seventh appearance at the Olympics. Five athletes from American Samoa were selected to the Games; all of them were given under Universality slots and tripartite invitation, without being qualified. Freestyle swimmer Ching Maou Wei became the nation's first male flag bearer at the opening ceremony since 1996. Among the sports played by the athletes, American Samoa also marked its Olympic return in wrestling after 16 years. American Samoa, however, has yet to win its first ever Olympic medal.
Cyprus competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016. This was the nation's tenth consecutive appearance at the Summer Olympics.
