Swimming at the 2012 London Summer Games:

China's Sun Yang was heavily favored, having won World titles in 2011 in the 800 and 1,500 metres. His 2011 championship in this event was done in the world record time of 14:34.14. Coming into this event he had already won a gold medal in London in the 400 metres. He qualified easily in this event but then in the final strangely jumped into the water ahead of the signal, but what seemed to be a false start was waved off as due to crowd noise. On the second start he moved into the lead early and was never challenged. At 400 metres he was 1.23 seconds ahead of his world record split from the Shanghai Worlds. At 1,000 metres Sun was over five seconds ahead of Canadian Ryan Cochrane, the 2008 bronze medalist, with the defending champion, Oussama Mellouli, who was fighting off a shoulder injury, moving into third place. Park Tae-Hwan, the Korean gold medalist at 400 metres in 2008, and runner-up in that event to Sun in London, was also close to a medal position.

But the race belonged only to Sun. He did not slow at all, finishing in 14:31.02 to easily better his own world record and win the gold medal by over eight seconds, as Cochrane came in second in 14:39.63, with Mellouli winning a second consecutive medal in the event in 14:40.31. Park had nothing left, and dropped well back of Mellouli, but still finished fourth. Mellouli would come back in a few days and win the 10 km open-water swim, the first ever swimmer to win gold medals both in the pool and open-water. Sun's win made him the seventh swimmer to win both the 400 and 1,500 metre freestyles at one Games.