Introduction: the interconnected nature of contemporary population movements and global health. The introduction establishes the book’s scope of treatment, central themes, and reasons to care about migration and global health. The author’s principal concern is with the multiple, multiplying, and underexplored interconnections of transnational mobility and health. The geo-political contexts for analysis include the South, the North, South-North interfaces, and glocal interdependence. Unequal mobilities - the transnational interplays of education, occupation, competencies, and resources with migration and health - provide the unique framework for analysis. Structural determinants and policy facilitators and constraints fill out the framework. The fragmented landscape of global health governance receives special attention. Then, the introduction distinguishes global health as a field of study and practice. Arising chronic health demands along with communicable-health concerns are particularly challenging in the Global South at the same time that poor countries experience the “fatal flow of expertise.” Individual and family health strategies and prospects associated with unequal population movements of different types (proactive and reactive, short term and long term, distant and proximate, recognized and irregular) are considered. Two recurring dynamics shape the choice of the thematic cases selected for attention in the chapters that follow: (1) the presence of a robust and important transnational mobility-health interface that unmasks and illuminates (2) the glocal health and well-being consequences of unequal mobility. Practical approaches to addressing the determinants of unequal mobility and health conditions are incorporated throughout.