Migrant transnationalism is a central theme in migration research. It was defined 25 years ago as ‘the processes by which immigrants forge and sustain multi-stranded social relations that link together their societies of origin and settlement’ (Basch et al. 1994:6). The subsequent decades saw a burgeoning of research on transnationalism and specific aspects of it, including transnational families, remittances, and transnational social protection. However, there has also been a backlash against the phenomenon of transnationalism, arguing that it is sometimes exaggerated beyond its empirical significance and sometimes used so broadly that it loses analytical value. In this webinar, we ask how ‘migrant transnationalism’ should be understood and delimited today, and what directions future research should take.