Demographic change is arguably one of the central drivers of social change in general and of challenges to the post-war ‘welfare-state compromise’ that formed the basis of T.H. Marshall’s (1950) conception of citizenship more particularly. In what follows, we review some of the more significant developments in population dynamics in recent decades, and explore their relationship to the prospects of citizenship in years to come. We believe that the relationship between demography and citizenship has been too often overlooked or underestimated in citizenship studies and urge here a reconsideration of this crucial relationship.