Return migration and migrant transnationalism are key phenomena in research on international migration. Here we examine how the two are connected. The article introduces a special section and draws partly upon this selection of papers and partly upon the broader literature. First, we argue that there is often a blurred boundary between mobility as a transnational practice, for instance in the form of return visits, and purportedly permanent or long-term return migration. Second, we examine the effects of transnationalism on return migration intentions and experiences. Third, we explore how migration trajectories, involving various forms of ‘return’ moves, create different forms of transnationalism. Examples include the ‘reverse transnational’ practices of returnees and the ‘residual transnationalism’ of migrants who have had an unsuccessful return experience and decided to settle permanently abroad. We end by considering how both return migration and transnationalism exist in the interplay between the personal and the social.