Galleanisti are followers or supporters of the insurrectionary anarchist Luigi Galleani, who operated most notably in the United States following his immigration to the country. The vast majority of Galleanisti or Galleanists were similarly poor and working class Italian immigrants or Italian Americans, and especially Italian anarchists and Italian immigrants or Italian-Americans involved in the labor movement of the time. Galleanists remain the primary suspects in a campaign of bombings between 1914 and 1920 in the United States.

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.