Japan, represented by Japanese Olympic Committee, competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. Despite being London's third Olympic Games, Japan marked their London debut at this games. The nation also celebrated its centennial anniversary in the Olympics, having participated at every games since 1912 except for two editions; it was not invited to the 1948 Summer Olympics in London for its role in World War II, and was also part of the US-led boycott of the 1980 Summer Olympics in Moscow. Japan sent a total of 295 athletes to the Games, 138 men and 157 women, to compete in 24 sports.
New Zealand competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's twenty-fourth appearance at the Olympics. The New Zealand Olympic Committee sent 184 athletes, 97 men, and 87 women to the Games to compete in 16 sports, the nation's largest ever delegation.
Mexico competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's twenty-second appearance at the Olympics since its debut in 1900. Comité Olímpico Mexicano sent a total of 102 athletes to the Games, 64 men and 38 women, to compete in 23 sports. Men's football was the only team sport in which Mexico was represented at these Olympic Games. There was only a single competitor in badminton, sprint canoeing, and table tennis.
South Korea competed at the 2012 Summer Olympics in London, from July 27 to August 12, 2012. This was the nation's sixteenth appearance at the Olympics, having missed the 1980 Summer Olympics in Moscow because of its support for the United States boycott. The Korean Olympic Committee sent the nation's smallest delegation to the Games since 1992. A total of 248 athletes, 135 men and 113 women, competed in 22 sports.
Switzerland competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. Swiss athletes have competed at every Summer Olympic Games in the modern era, except when they boycotted the 1956 Summer Olympics in Melbourne in protest of the Soviet invasion of Hungary. The Swiss Olympic Association sent a total of 103 athletes to the 2012 Games, 72 men and 31 women, to compete in 18 sports.
Gabon competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's ninth appearance at the Olympics; the nation did not participate at the 1976 Summer Olympics in Montreal and 1980 Summer Olympics in Moscow, affected by the African and the American-led boycott, respectively.
The Belarus national under-23 football team represented Belarus in international football competitions in Olympic Games. The selection is limited to players under the age of 23 however the Olympics allows for the addition of up to three overage players. The team is controlled by the Football Federation of Belarus (BFF). Belarus made its first appearance in football at the 2012 Olympics in London.
The men's football tournament at the 2012 Summer Olympics was held in London and five other cities in Great Britain from 26 July to 11 August. Associations affiliated with FIFA were invited to enter their men's U-23 teams in regional qualifying competitions, from which 15 teams, plus the hosts Great Britain, reached the final tournament. Men's teams were allowed to augment their squads with three players over the age of 23. It was the first men's Olympic football tournament to feature a team representing Great Britain since the 1960 Summer Olympics in Rome. The competition also marked Uruguay's men's football team's first Olympic appearance since 1928, when it won its second consecutive gold medal.
The women's football tournament at the 2012 Summer Olympics was held in London and five other cities in the United Kingdom from 25 July to 9 August. Associations affiliated with FIFA were invited to enter their women's teams in regional qualifying competitions, from which 11 teams, plus the hosts Great Britain reached the final tournament. There are no age restrictions for the players participating in the tournament. It is the first major FIFA affiliated women's tournament to be staged within the United Kingdom, and marked the first time a team representing Great Britain took part in the women's tournament.
The 2012 United States women's national soccer team season was dominated by the 2012 Women's Olympic Football Tournament. The start of the year saw the team compete in the CONCACAF Olympic qualifying tournament and then in July they participated in the main event itself. The team won both tournaments. In between they also played in Algarve Cup, the Kirin Challenge Cup and the 2012 Sweden Invitational. They also won the latter tournament.
Honduras 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, excluding the 1972 Summer Olympics in Munich, and the 1980 Summer Olympics in Moscow, because of the American-led boycott.
The Switzerland national under-23 football team represents Switzerland in international football competitions in the Olympic Games. The selection is limited to players under the age of 23. However, the Olympics allows for the addition of up to three overage players. The team is controlled by the Swiss Football Association (ASF/SFV). In three previous appearances, Switzerland have won one silver medal at the 1924 Olympics in Paris.
Group A of the men's football tournament at the 2012 Summer Olympics took place from 26 July to 1 August 2012 in Cardiff's Millennium Stadium, Coventry's City of Coventry Stadium, London's Wembley Stadium and Manchester's Old Trafford. The group contained host nation Great Britain, Senegal, United Arab Emirates and Uruguay.
Group C of the men's football tournament at the 2012 Summer Olympics took place from 26 July to 1 August 2012 in Cardiff's Millennium Stadium, Coventry's City of Coventry Stadium, Glasgow's Hampden Park, Manchester's Old Trafford and Newcastle's St James' Park. The group contained Belarus, Brazil, Egypt and New Zealand.
Group D of the men's football tournament at the 2012 Summer Olympics took place from 26 July to 1 August 2012 in Coventry's City of Coventry Stadium, Glasgow's Hampden Park, Manchester's Old Trafford and Newcastle's St James' Park. The group contained Honduras, Japan, Morocco and Spain.
The 2012 Summer Olympics Football Final was a football match that took place at Wembley Stadium in London, United Kingdom on 11 August 2012 to determine the winner of the men's football tournament at the 2012 Summer Olympics. It was the 23rd final of the men's football tournament at the Summer Olympics, a quadrennial tournament contested for the men's under-23 national teams of FIFA to decide the Olympic champions.
Mexico 
South Korea 
Gabon 
Switzerland 
