Do states have a moral right to restrict immigration as they see fit? Or should individuals be free to cross international borders and settle in whatever country they choose? Those who defend a right to exclude base their arguments on principles of freedom of association, associative ownership, freedom from imposed obligations, communal independence and national self-determination. In the opposite camp, a right to international freedom of movement is defended by way of an analogy between international and domestic mobility, and on comprehensive theories of justice ranging from libertarianism to liberal egalitarian contractualism. Finally, there are views that criticise the right to exclude without endorsing a universal right to freedom of movement. These include the view that immigration restrictions should be evaluated with an eye to global distributive concerns, and the view that immigration restrictions would have to be sanctioned by a global demos to be legitimate. This chapter gives an overview of this controversy about the justifiability of restrictions on immigration. It closes with some desiderata for future research on the duties of various agents under non-ideal circumstances.