This article asks whether states have a right to close their borders because of their right to self-determination, as proposed recently by Christopher Wellman, Michael Walzer, and others. It asks the fundamental question whether self-determination can, in even its most unrestricted form, support the exclusion of immigrants. I argue that the answer is no. To show this, I construct three different ways in which one might use the idea of self-determination to justify immigration restrictions and show that each of these arguments fails. My conclusion is that the nature and value of self-determination have to do with the conditions of genuine self-government, not membership of political society. Consequently, the demand for open borders is fully...