A global city (also known as a power city, world city, alpha city, or world center) is a city that serves as a primary node in the global economic network. The concept originates from geography and urban studies, based on the thesis that globalization has created a hierarchy of strategic geographic locations with varying degrees of influence over finance, trade, and culture worldwide. The global city represents the most complex and significant hub within the international system, characterized by links binding it to other cities that have direct, tangible effects on global socioeconomic affairs.

The criteria of a global city have varied over time and depending on the source; common features include a high degree of urban development, a large population, the presence of major multinational companies, a significant and globalized financial sector, well developed and internationally linked transportation infrastructure, local or national economic dominance, high quality educational and research institutions, and a globally influential output of ideas, innovations, or cultural products. Quintessential examples, based on most indices and research, include New York City, London, Paris, and Tokyo.