Until recently political philosophy addressed the normative issues of justice, freedom, democracy and citizenship mainly within the frame of reference of a bounded state. Growing awareness that these issues transcend this frame, and the increased political salience of international migration have brought discussions of migration to the fore. Fundamental issues include the justification for and constraints on states’ control over entry to and residence within their borders, the grounds for awarding or withholding citizenship, and the relative weight of the claims of states and citizens vis-a-vis outsiders in general and special cases such as refugees, family members and stateless persons. There is a tension between liberal approaches based on universal individual freedom and equality, and those based on communal commitments or democratic self-determination, sometimes framed as a tension between justice or human rights, and community or democracy. It is also contested whether political philosophers should aim to provide foundational ideals, critical norms or concrete policy guidance, to what extent appropriate answers depend on particular contexts, and what count as salient contextual considerations. Areas requiring further research include (a) articulating more precisely what may be distinctive about territorial jurisdiction and self-determination for the justification and limits of states’ rights to control boundaries and to determine the citizenship status of individuals, (b) transcending methodological nationalism to consider the treatment of migration, participation and membership issues at sub-national, transnational and supranational levels and (c) addressing the particular implications for justice of the increasing and diverse migration likely to accompany climate change.