Abstract Diaspora is a defining condition of the history of the past century, a prehistory to our disastrous moment in time and also the foundation of our political landscape. Yet it is notably absent in much art-historical discussion of modernism, despite the fact that the experiences of diaspora and migration are often embedded in the lives of modernist artists and other actors; in the formations, networks, and dispersals of modernist institutions and group affiliations; and in the deployment of characteristically modernist artistic strategies (temporal fragmentation, collage, montage, and the readymade) that manifest a dialectical entanglement of self and other. This essay ponders the disconnect between the historical structures of modernism in art and its theorization, and considers the questions: Can diaspora and diasporic thinking help further our understanding of the twentieth century in art? Can it help us in reconsidering modernism from a diasporic perspective today? As prompts for further thought, the text considers four historical episodes in which ideas of diaspora, modernity, and modernism are entwined: W.E.B. Du Bois and the First Universal Races Congress in London 1911; Georg Simmel, Du Bois, and Alain Locke in Berlin and the emergence of a matrix of modern sociological thinking; Mikhail Bakhtin in exile in Kazakhstan and the formation of his dialogical philosophy of language; and Aaron Douglas and Meyer Shapiro at the First American Artists’ Congress in 1936 and in the pages of Art Front.