The swimming competitions at the 2012 Summer Olympics in London took place from 28 July to 4 August at the Aquatics Centre. The open-water competition took place from 9 to 10 August in Hyde Park.
Swimming featured 34 events (17 male, 17 female), including two 10 km open-water marathons in Hyde Park's Serpentine Lake. The remaining 32 were contested in a 50 m long course pool within the Olympic Park.