This handbook covers various facets relating to international migration, international relations, and security in Asia, addressing the growing importance of these issues in our interconnected world. International migration is a complex phenomenon with far-reaching implications for individuals, societies, and states. Understanding the drivers, patterns, and consequences of migration is critical for policymakers, scholars, and the broader public to address the challenges and opportunities it presents. This comprehensive reference work - organised across ten sections for broad regional representation including Southeast and East Asia, Central and South Asia - examines the interplay between international relations and migration to provide insight into how geopolitical dynamics, conflict, and cooperation influence migration flows and policies. The study of security in Asia and beyond is of paramount importance given the geopolitical importance of the region and evolving security challenges. It is home to diverse and dynamic nations with complex relationships ranging from territorial disputes to transnational threats such as terrorism and cybersecurity. Analysing security concerns in this context provides valuable insights into the strategies, alliances, and policies employed by states to counter emerging threats and promote regional stability. The book contributes to this existing body of knowledge by bringing together diverse perspectives, empirical research, and theoretical frameworks into a sweeping regional overview of the most topical issues in migration. It serves as a valuable resource for scholars in political science, sociology, economics, anthropology, and law, focused on global migration dynamics, international relations, and security challenges in Asia and globally, and for policymakers, providing evidence-based insights for decision-making processes and effective policy design. The book promotes informed discussions about migration in all its multifacetedcomplexity - from angles that address gender, the environment, trade and economics, governance, diaspora, diplomacy, and crime and trafficking, to name but a few. In doing so, it speaks to numerous aspects of the Sustainable Development Goals, and contributes to the pursuit of peace and prosperity in an increasingly interconnected world.