Over 10,000 athletes from 204 National Olympic Committees (NOCs) are expected to participate, surpassing the 1948 Summer Olympics in London and the 2002 Commonwealth Games in Manchester as the largest multi-sport event ever to be held in the United Kingdom.
The Netherlands Antilles Olympic Committee, which had planned to continue functioning after the dissolution of the Netherlands Antilles, had its membership withdrawn by the IOC Executive Committee at the IOC session of June 2011. However, Dutch Antillean athletes who qualify for the 2012 Olympics will be allowed to participate independently under the Olympic flag. As South Sudan has no recognized NOC, South Sudanese track and field athlete Guor Marial will also be participating independently in the Games.
There were initial concerns about Saudi Arabia, Qatar and Brunei not sending any female athletes to the games: nevertheless, the Saudi team eventually sent two women.
