This chapter sets out a 'mobile political ecology' conceptual framework for understanding how migration links to vulnerability and resilience across diverse envrionmental, social and policy contexts. The chapter draws from and frames empirical work in Cambodia, Myanmar, Laos, Thailand, the Philippines, Vietnam, Indonesia and Malaysia, demonstrating the value of 'progressive contextualisation' for tracing vulnerability in migration-flood contexts. The chapter is part of a book that is the key output from primary research funded by the Rockefeller Foundation