 This entry begins with a definition and provides an overview of European debates about colonialism and anti- and post-colonial critiques by theorists from settler-colonial societies and the Global South. The second section explains how European thinkers justified, legitimized, and challenged dispossession and political domination. The third section focuses on liberalism and the fourth section briefly discusses the Marxist tradition, including Marx’s own defense of British colonialism in India and Lenin’s anti-imperialist writings. The fifth section provides an introduction to contemporary “post-colonial theory.” This approach has been particularly influential in literary studies because it draws attention to the diverse ways that postcolonial subjectivities are constituted and resisted through discursive practices. The final section will introduce Indigenous critiques of settler-colonialism that emerge both as a response to colonial practices of domination and dispossession of land, customs and traditional history and to post-colonial theories of universalism. The goal of the entry is to provide an overview of the philosophical response to the experience of European colonization.