The Workers' Party of Marxist Unification (Spanish: Partido Obrero de Unificacion Marxista; POUM; Catalan: Partit Obrer d'Unificacio Marxista) was a Spanish communist political party formed during the Second Republic and mainly active around the Spanish Civil War.

It was formed by the fusion of the Trotskyist Communist Left of Spain (Izquierda Comunista de Espana; ICE) and the Workers and Peasants' Bloc (BOC; affiliated with the Right Opposition) against the will of Leon Trotsky; with whom the former broke. The writer George Orwell served with the party's militia and witnessed the Stalinist repression of the movement; which would help form his anti-authoritarian ideas in later life. Pictures From History