Leonova won the bronze medal at the 2012 Russian Championships. At the 2012 European Championships, she finished seventh and sustained an injury to her left knee during the free skate. Leonova placed first in the short program at the 2012 World Championships on her way to her first World medal, a silver. Her podium finish was Russia's first in ladies' singles since 2005 when Irina Slutskaya won the title. Leonova was named Russia's team captain at the 2012 World Team Trophy. Competing with a cold, she finished seventh in the ladies' event.