Citizenship has provided a focus for many of the most significant arguments about justice and democracy. Major theorists of justice, for instance, have tried to understand its contours by thinking through the question of what rights and entitlements fellow citizens ought to enjoy. Theoretical reflections on democracy have also often assumed a context of a single political community: generally the nation-state. Nevertheless, increasing numbers of theorists are arguing that both democracy and justice need to be de-coupled from the nation-state and re-imagined in other, trans-national or global contexts. If so, can the concept of citizenship still do important work in illuminating those debates? This book explores the continued ability of the concept of citizenship to do valuable work in spelling out what a commitment to justice and democracy implies in a world marked by inequalities, migration flows, and various historical injustices, whilst at the same time addressing profound questions about the boundaries of citizenship, participation and political membership. This book was originally published as a special issue of Critical Review of International Social and Political Philosophy.