[2] Swimming featured 34 events (17 male, 17 female), including two 10 km open-water marathons in Hyde Park's Serpentine Lake.

The United States claimed a total of 31 medals (16 golds, 9 silver, and 6 bronze) in the leaderboard to maintain its supremacy as the most successful nation in swimming.

[3] For the first time since 1992, Australia delivered an underwhelming performance with only a single triumph in the freestyle relay, but managed to bring home a total of ten medals.

[6] After not winning a gold in swimming since 2000, Japan produced the most medals in the post-war era to build a tally of eleven (three silver and eight bronze).

Similar to the program's format in 2008, swimming featured a total of 34 events (17 each for men and women) including two 10 km open-water marathons.

Each relay event featured 16 teams, composed of: The men's and women's 10 km races at the 2012 Olympics each featured 25 swimmers: FINA announced in early July 2012 that 631 athletes from 166 nations would compete in swimming events at the 2012 Olympics (note: all nations qualified for the 10 km races also had at least 1 swimmer qualified for the pool portion).

[12] Brunei, Central African Republic, Djibouti, Ethiopia, Lesotho, Liechtenstein, Togo, and Tonga made their official debut in swimming.

In the final of the 100-metre breaststroke, South African Cameron van der Burgh won in a world-record time of 58.46, bettering the previous record of 58.58 held by Brenton Rickard of Australia.