Insurrectionary anarchism is a revolutionary theory and tendency within the anarchist movement that emphasizes insurrection as a revolutionary practice. It is critical of formal organizations such as labor unions and federations that are based on a political program and periodic congresses. Instead, insurrectionary anarchists advocate informal organization and small affinity group based organization. Insurrectionary anarchists put value in attack, permanent class conflict and a refusal to negotiate or compromise with class enemies.

Italian anarchism as a movement began primarily from the influence of Mikhail Bakunin, Giuseppe Fanelli, and Errico Malatesta. Rooted in collectivist anarchism and social or socialist anarchism, it expanded to include illegalist individualist anarchism, mutualism, anarcho-syndicalism, and especially anarcho-communism. In fact, anarcho-communism first fully formed into its modern strain within the Italian section of the First International. Italian anarchism and Italian anarchists participated in the biennio rosso and survived Italian Fascism, with Italian anarchists significantly contributing to the Italian Resistance Movement. Platformism and insurrectionary anarchism were particularly common in Italian anarchism and continue to influence the movement today. The synthesist Italian Anarchist Federation appeared after the war, and autonomismo and operaismo especially influenced Italian anarchism in the second half of the 20th century.