This article introduces some of the key philosophical contributions of W. E. B. Du Bois. Du Bois studied with Santayana and William James (among others), but chose social science, social theory, journalism, and activism over academic philosophy. Despite this detour, the philosophic depth of his work has won the attention of scholars in fields such as history, English, post-colonial theory, African-American Studies, American philosophy, and Africana philosophy, and it has belatedly begun to attract the interest of philosophers more generally. This brief overview will explore the philosophical dimensions of some of Du Bois’s best-known positions – his claims about the ‘color line’ and the Talented Tenth, his argument with Booker T. Washington, and his account of double-consciousness. These positions open onto a rich constellation of views in social ontology, epistemology, political theory, existential phenomenology, and more besides.