Also known as London 2012, the 2012 Summer Olympics was a major international multi-sport event, celebrated in the tradition of the Olympic Games, as governed by the International Olympic Committee (IOC), that took place in London, United Kingdom, from 27 July to 12 August 2012. The first event, the group stages in women's football, began two days earlier, on 25 July. More than 10,000 athletes from 204 National Olympic Committees (NOCs) participated.
Following a bid headed by former Olympic champion Sebastian Coe and then-Mayor of London Ken Livingstone, London was selected as the host city on 6 July 2005 during the 117th IOC Session in Singapore, defeating bids from Moscow, New York City, Madrid and Paris. London was the first city to officially host the modern Olympic Games three times, having previously done so in 1908 and in 1948.
The Games received widespread acclaim for their organisation, with the volunteers, the British military, and public enthusiasm praised particularly highly. The opening ceremony, directed by Danny Boyle, also received near-universal acclaim. During the Games, Michael Phelps became the most decorated Olympic athlete of all time, winning his 22nd medal. Great Britain achieved its highest tally of gold medals since 1908, finishing third in the medal table. Saudi Arabia, Qatar and Brunei entered female athletes for the first time, meaning every currently eligible country has sent a female competitor to at least one Olympic Games. With women's boxing included, the Games became the first at which every sport had female competitors.