This report reviews airport system development in Asian megacities and provides policy recommendations to support cities' economic competitiveness, growth, and sustainability. The report looks at how airport system development can affect cities' spatial configuration and economic productivity, and draws on case studies from Indonesia, Japan, the Philippines, the People's Republic of China, and Viet Nam. It assesses multi-airport formations, airport relocation, ground transportation, and land planning. The report highlights the importance of multilevel governance in ensuring the development of dynamic airport systems that support the growth and sustainability of the region's megacities.