Mega-regions have emerged as ‘new engines’ of global economic growth, characterized by incessant movement of global and local capital. Considering this, this study offers a spatiodemographic approach that defines mega-regions beyond static state-delimited urban boundaries, and considers the global-local dynamics that underlie its formations. Focusing on the Philippines, one of the fastest growing economies in Southeast Asia, we discuss emergent mega-regions and analyze their recent and future trajectories using municipal-level demographic variables (population density, percentage change across Censal years 1990, 2000, 2010) along with special economic zones. Results show the rise of multiple mega-regions in varying degrees of spatial expansion and development from the mega-conurbation of Metro Manila and surrounding regions to emergent provincial mega-regions. Also, the patterns of special economic zones illustrate the spatial expressions of globalization in restructuring mega-regional landscapes in the Philippines. The paper hopes to encourage urban analyses that seek ways of theorizing and accounting for mobilities and global-local networks to guide socially just and sustainable planning.