ABSTRACT In this introduction to the special issue Contested Categories in the Context of International Migration, we argue for the importance of critically engaging with state-created categories and classification systems. We advocate doing so in the particularly convoluted context of international migration, where states use categories to manage migrants’ entry, reception, and residence, making categorisation extremely consequential for individual migrants, even though bureaucratic documentation and everyday understandings of categories often differ greatly between migrants’ home countries and receiving states. We outline some of the scholarship on categorisation that has inspired our thinking, discuss why migration is such an important and generative site for examining categories and processes of categorisation, and finally consider how the contributions in this special issue attest to this.