The Kuleshov effect is a film editing (montage) effect demonstrated by Soviet filmmaker Lev Kuleshov in the 1910s and 1920s. It is a mental phenomenon by which viewers derive more meaning from the interaction of two sequential shots than from a single shot in isolation.

Kuleshov edited a short film in which a shot of the expressionless face of Tsarist matinee idol Ivan Mosjoukine was alternated with various other shots (a bowl of soup, a girl in a coffin, a woman on a divan). The film was shown to an audience who believed that the expression on Mosjoukine's face was different each time he appeared, depending on whether he was "looking at" the bowl of soup, the girl in the coffin, or the woman on the divan, showing an expression of hunger, grief, or desire, respectively. The footage of Mosjoukine was actually the same shot each time. Vsevolod Pudovkin (who later claimed to have been the co-creator of the experiment) described in 1929 how the audience "raved about the acting... the heavy pensiveness of his mood over the forgotten soup, were touched and moved by the deep sorrow with which he looked on the dead child, and noted the lust with which he observed the woman. But we knew that in all three cases the face was exactly the same."

Kuleshov used the experiment to indicate the usefulness and effectiveness of film editing. The implication is that viewers brought their own emotional reactions to this sequence of images, and then moreover attributed those reactions to the actor, investing his impassive face with their own feelings. Kuleshov believed this, along with montage, had to be the basis of cinema as an independent art form.[