Semyonova started her season at the Russian National Championships, where she placed second in the all around to junior Aliya Mustafina. She won the uneven bars and floor exercise to book her place on the European championships squad. Semyonova placed first in the all-around competition at the 2009 European Championships in Milan, Italy, just ahead of her teammate Afanasyeva. In the event finals, she was second on the uneven bars behind Beth Tweddle of the United Kingdom and third on floor, behind Tweddle and the 2006 World Champion, the Italian Vanessa Ferrari. Semyonova also qualified for the balance beam final and finished in fifth place with an uncharacteristically shaky routine. In July she suffered a minor injury to her wrist, keeping her out of the Russian Cup, but was confirmed to the Russian team for the world championships in October along with Yekaterina Kurbatova, Anna Myzdrikova and Afanasyeva, who eventually withdrew due to an injury. After a qualifying round marred by wobbles and a fall on her floor routine, she was 10th going into the all-around but failed to make any event finals. Another fall from the uneven bars during the first rotation prevented her from a better placement and she finished 13th overall.