Great Britain and Northern Ireland, represented by the British Olympic Association (BOA), competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012 as the host nation and the team of selected athletes was officially known as Team GB. British athletes have competed at every Summer Olympic Games in the modern era, alongside Australia, France and Greece, though Great Britain is the only one to have won at least one gold medal at all of them. London was the first city to host the Summer Olympics on three different occasions, having previously done so in 1908 and 1948. It was joined by Paris in 2024 and will be joined by Los Angeles in 2028 in hosting the Olympic Games for a third time. Team GB, organised by BOA, sent a total of 541 athletes, 279 men and 262 women, to the Games, and won automatic qualification places in all 26 sports.
The government agency UK Sport targeted a total of 48 to 70 medals, with a commitment of at least a minimum amount, one more than the team won at the 2008 Summer Olympics, and a fourth-place finish in the medal table. On 7 August 2012, Great Britain had reached its 48-medal target, and surpassed the 19 gold-medal tally from Beijing the previous Summer Olympics, making it the most successful Olympics since 1908.