Migration is now firmly embedded as a leading global policy issue of the twenty-first century. While not a new phenomenon, it has altered significantly in recent decades, with changing demographics, geopolitics, conflict, climate change and patterns of global development shaping new types of migration. Such movement involves an increasingly diverse group of people, as well as shifting countries of origin, transit and destination in what is often a complex, multi-staged and at times lengthy process. This introductory chapter examines these changes and sets out the main themes underpinning the Handbook. The book is organised into six main sections: theories and models of migration; rights and deservingness; vulnerability and precarity; specific healthcare needs and priorities; healthcare provision; and transnational and diasporic networks. The chapters in the book are, in turn, underpinned by three common themes: (1) the intersectional nature of migration and health; (2) the broad neoliberal context within which many experiences of migration and health take place; and (3) the need to move beyond a ‘one-size fits all’ approach to health and healthcare to recognise how subjective perspectives, priorities and responses feed in to ideas about, and experiences relating to, health, treatment seeking and care.