The Power of Darkness (Russian: Власть тьмы, Vlast' t'my) is a five-act drama by Leo Tolstoy. Written in 1886, the play's production was forbidden to be produced in Russia until 1902, mainly through the influence of Konstantin Pobedonostsev. In spite of the ban, the play was unofficially produced and read numerous times.

The central character is a peasant, Nikita, who seduces and abandons a young orphan girl Marinka; then the lovely Anisija murders her own husband to marry Nikita. He impregnates his new stepdaughter, then, under his wife's influence, murders the baby. On the day of his stepdaughter's marriage, he surrenders himself and confesses to the police.