Lezak qualified for his fourth Olympics at the 2012 United States Olympic Trials in Omaha, Nebraska. His sixth-place finish in the Olympic Trial finals was good enough to reach the London Games as a member of the U.S. 4×100-meter freestyle relay team. At the 2012 Summer Olympics in London, United Kingdom, Jimmy Feigen, Matt Grevers, Ricky Berens and Lezak swam for the U.S. team in the preliminaries. Nathan Adrian, Michael Phelps, Cullen Jones and Ryan Lochte swam in the finals, and together all these competitors earned a silver medal for the team's second-place finish in the finals. Lezak became the first male swimmer in Olympic history to win four medals in the same event, the 4×100-meter freestyle relay.