Klimenko competed at the 2018 European Women's Artistic Gymnastics Championships where Russia won team silver behind Italy. Individually Klimenko won uneven bars gold and bronze in the all-around behind Giorgia Villa of Italy and Amelie Morgan of Great Britain. She was later selected to represent Russia at the 2018 Youth Olympics taking place in Buenos Aires, Argentina. There she qualified in third place to the floor exercise and balance beam finals and in fifth place to the individual all-around final and to the uneven bars final. In the individual all-around final she faltered on uneven bars and vault and once again finished in fifth place, making her the first Russian to not win the all-around since the inception of the Youth Olympic Games. She later won gold in the uneven bars finals, matching the result of previous Russian Youth Olympic athletes Viktoria Komova and Seda Tutkhalyan. She also won silver on the balance beam behind Tang Xijing of China and placed seventh on floor exercise after a fall.