At the 2012 Summer Olympics in London, Hardy won her first Olympic medal, a bronze, in the 4×100-meter freestyle with Missy Franklin, Lia Neal and Allison Schmitt, when the U.S. team finished third behind the teams from Australia and the Netherlands. Swimming the second leg, Hardy had a split of 53.53 seconds and the team finished with a total time of 3:34.24, an American record. She also earned a gold medal by swimming for the winning U.S. team in the preliminary heats of the 4×100-meter medley relay. In her two individual events, she finished seventh in the 50-meter freestyle and eighth in the 100-meter freestyle.