I defend a cosmopolitan theory of the right to secede according to which a group has a right to secede only if it is better from a cosmopolitan point of view. I defend the theory by arguing that the right to political self-determination is not strong enough to support the other main theories of secession on offer, and by arguing that there are a number of advantages to approaching the right to secede in this deflationary way, especially given the commitments of cosmopolitanism in political philosophy more generally.