Autonomism, also known as autonomist Marxism is an anti-capitalist left-wing political and social movement and theory. As a theoretical system, it first emerged in Italy in the 1960s from workerism (operaismo). Later, post-Marxist and anarchist tendencies became significant after influence from the Situationists, the failure of Italian far-left movements in the 1970s, and the emergence of a number of important theorists including Antonio Negri, who had contributed to the 1969 founding of Potere Operaio as well as Mario Tronti, Paolo Virno and Franco "Bifo" Berardi.

George Katsiaficas summarizes the forms of autonomous movements saying that "In contrast to the centralized decisions and hierarchical authority structures of modern institutions, autonomous social movements involve people directly in decisions affecting their everyday lives, seeking to expand democracy and help individuals break free of political structures and behavior patterns imposed from the outside". This has involved a call for the independence of social movements from political parties in a revolutionary perspective which seeks to create a practical political alternative to both authoritarian/state socialism and contemporary representative democracy.

Autonomism influenced the German and Dutch Autonomen/Autonomen, the worldwide social centre movement and today is influential in Italy, France and to a lesser extent the English-speaking countries. Those who describe themselves as autonomists now vary from Marxists to anarchists.