The article provides an introduction into this EJEAS issue on democratisation and international migration. Third Wave democratisation and the recent unprecedented increase in international labour migration may have the same structural origins, but so far few attempts have been made to link the two research agendas. One explanation might be that existing research on democratisation has neglected the exogenous dimension, and that migration research was preoccupied with destination countries. By drawing from the contributions to this Issue and the literature on norm diffusion, we argue that migrants have the potential to act as norm entrepreneurs and as agents of democratisation. The article maps out three avenues of norm diffusion: Migration can be the cause for changes of political attitudes at the individual level, it can be an enabling factor for collective action and it may lead to institutional change at the national and global level. To further assess how precisely these pathways might support or impede democratisation, more theory-guided empirical studies on the subject are urgently needed.