Twelve Months (世界名作童話 森は生きている, Sekai Meisaku Dōwa: Mori wa Ikiteiru, lit. 'World Masterpiece Fairy Tales: The Forest That Lives'; Russian: Двенадцать месяцев, romanized: Dvenadcať mesjacev) is a 1980 animated feature film directed by Yugo Serikawa, Kimio Yabuki and Tetsuo Imazawa, produced by Toei Animation from Japan in partnership with Soyuzmultfilm from the Soviet Union. It was based on the 1943 play written by Samuil Marshak which itself was based on the medieval fairy tale of the same name. The music was composed by Vladimir Ivanovich Krivtsov and performed by the National Leningrad Philharmonic under the direction of A. S. Dmitriev.

Preceded by The Wild Swans (1977) and Thumbelina (1978), and followed by Swan Lake (1981) and Aladdin and the Wonderful Lamp (1982), it represents the third episode in Toei's World Masterpiece Fairy Tales movie series.