Boris Mikhailovich Eichenbaum (Борис Михайлович Эйхенбаум) was a leading figure in the Russian formalist school of literary scholars, critics and theorists. An early member of OPOYAZ (Общество изучения Поэтического Языка, Society for the Study of Poetic Language) and a prominent member of the school, Eichenbaum propounded the latter’s central claims during its period of highest visibility in the first half of the 1920s and also defended it against attack from revolutionary thinkers (like Leon Trotsky) who rejected Formalism for its supposed lack of social-historical engagement.