Can Kantian cosmopolitanism contribute to normative approaches to immigration? Kant developed the universal right to hospitality in the context of late eighteenth-century colonialism. He claimed that non-European countries had a sovereign right over their territory and the conditions of foreigners' visits. This sovereign prerogative limited visitors' right to hospitality. The interconnected and complementary system of right he devised is influential today, but this article argues that maintaining the complementarity of the three realms involves reconsidering its application to contemporary immigration. It situates Kant's Perpetual Peace within the context of debates about conquest and colonialism and argues that Kant's strict conception of sovereignty is justified by his concern in maintaining a realm of sovereignty that is complementary with cosmopolitanism and his prioritization of mutual agreements in each of the realms, particularly in a context of international power asymmetry. In Kant's time, European powers appropriated cosmopolitan discourses to defend their right to visit other countries and it was necessary to strengthen non-Europeans' sovereign claims. The strength and hostility of the visitors made limited hospitality and strong sovereignty act in tandem to keep away conquerors, expanding cosmopolitanism. Today, individuals from poor countries migrate to wealthier ones where they are subject to a sovereign authority that excludes them. Sovereignty and cosmopolitanism no longer work complementarily, but rather strengthen powerful state actors vis-à-vis non-citizens subject to unilateral rule. Maintaining the pre-eminence of the right to freedom, the article suggests that only through the creation of ‘cosmopolitan spaces’ of politics can we reproduce today the complementarity that Kant envisioned.