Providing a critical overview of transnationalism as a concept, this Handbook looks at its growing influence in an era of high-speed, globalised interconnectivity. It offers crucial insights on how approaches to transnationalism have altered how we think about social life from the family to the nation-state, whilst also challenging the predominance of methodologically nationalist analyses. Encompassing research from around the world, leading international researchers examine transnational migration, culture, state practices, organisations and institutions. Chapters draw attention to conceptual concerns around the topic, including the spatiality and temporality of transnationalism, connections to the life course, and the articulation of affect and emotion across borders. The Handbook further explains the transnational dimensions of different forms of migration, including labour migrations and student mobilities, and emphasises why and how transnational networks and circulations matter. An engaging foundation for students and scholars seeking to enhance their understanding of transnationalism, this Handbook offers agenda-setting arguments that will be beneficial to researchers of migration and mobilities, human geography, sociology, anthropology, international relations and cultural studies. It will also be an interesting read for practitioners working in migration, migrant rights and transnational organising and activism.