During the closing ceremony of the 2012 Summer Olympics in London, the flag bearers of 205 National Olympic Committees (NOCs) arrived into the main Olympic Stadium. The flag bearers from each participating country entered the stadium informally in single file, and behind them marched all the athletes without any distinction or grouping by nationality. The blending of all the athletes is a tradition that dates from the 1956 Summer Olympics, after a suggestion by Australian-born British student John Ian Wing, who thought it would be a way of bringing the athletes of the world together as "one nation." The flags of each country were not necessarily carried by the same flag bearer as in the opening ceremony.
2012 Summer Olympics closing ceremony flag bearers Wikipedia
Below is a list of all parading countries with their announced flag bearer, sorted in the order in which they appeared in the parade. This is sortable by country name under which they entered, the flag bearer's name, or the flag bearer's sport. Names are given as were officially designated by the International Olympic Committee (IOC).