Abstract: This paper takes as its centerpoint the critical category of “internal colonialism,” an important concept in both social movements and in sociology across different contexts. We trace a world-historical genealogy of the concept, focusing on North America (the United States), Latin America (Mexico and Bolivia), and South Asia (India), evaluating its epistemic-political values for critical theory, social research, and a politics of liberation today. While many scholars consider the concept passé, we argue, following scholars such as Silvia Rivera Cusicanqui, that internal colonialism is a key analytical framework that continues to be relevant. We emphasize three points. First, against internal colonialism formulations that characterize it as a US theory of race grounded upon debates of the 1960s–70s, we note its internationalist and transnational dimensions, and locate its significance in both framing struggles for self-determination and in critiques of the modern territorial state (national and/or imperial) and uneven development. Second, we locate internal colonialism as a category that can be brought into conversation with settler-colonial studies, the “decolonial turn,” and racial capitalism—an encouraging trend we already observe in recent literature. Third, we recenter internal colonialism’s significance in formulating a historically grounded, anti-capitalist, antiauthoritarian framework that eschews a liberal politics of multiculturalism and a neat Global North/South divide, calling instead for a transcalar methodology.