Marxism is a left-wing to far-left method of socioeconomic analysis that uses a materialist interpretation of historical development, better known as historical materialism, to understand class relations and social conflict and a dialectical perspective to view social transformation. It originates from the works of 19th-century German philosophers Karl Marx and Friedrich Engels. As Marxism has developed over time into various branches and schools of thought, no single, definitive Marxist theory exists.

In addition to the schools of thought which emphasize or modify elements of classical Marxism, various Marxian concepts have been incorporated and adapted into a diverse array of social theories leading to widely varying conclusions. Alongside Marx's critique of political economy, the defining characteristics of Marxism have often been described using the terms dialectical materialism and historical materialism, though these terms were coined after Marx's death and their tenets have been challenged by some self-described Marxists.

Marxism, as a school of thought has had a profound impact on society and global academia, having influenced many fields, including anthropology, archaeology, art theory, criminology, cultural studies, economics, education, ethics, film theory, geography, historiography, literary criticism, media studies, philosophy, political science, political economy, psychology, science studies, sociology, urban planning, and theatre.