Much contemporary anthropology is concerned with the origin, character, and consequences of late modernity. Surprisingly absent in this literature is the importance of population size, structure, and process. In particular, the demographic transition – or historical change from a high to a low equilibrium of birth and death rates – is an important component of modernity that deserves greater anthropological engagement. This review outlines demographic transition and transition theory, then discusses two ways in which transition intersects with literatures on modernity: through individual rationality and governmentality. Confronting both the material of population and the theories about it has the potential to significantly reconfigure anthropologies of the present.