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 is the first city to host the Summer Olympics on three different occasions, having previously done so in 1908 and 1948. Soon, it will be joined by Paris in 2024 and 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 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.