In his first event at the 2012 Summer Olympics in London, the 200-meter butterfly, Clary placed fifth in the final with a time of 1:55.06, which was slower than the times he posted in the heats (1:54.96) and semifinals (1:54.93). The final was won by Chad le Clos in a time of 1:52.96. In his second and last event of the Olympics, the 200-meter backstroke, Clary won in a time of 1:53.41, bettering Ryan Lochte's Olympic record of 1:53.94. Prior to this race, Clary held a personal best of 1:54.53 set in 2009. Going into the final, Clary posted the top times in the heats (1:56.24) and semifinals (1:54.71), but was not considered the favorite as Lochte was the defending Olympic and world champion. In the final of the 200-meter backstroke, Lochte lead Clary throughout the race and at the 150-meter mark, Clary was 0.12 seconds behind Lochte. During the last 50-meters however, Clary powered home with a split of 28.48, overtaking Lochte and winning gold. For Clary, it was also the first major international gold he won in his career.