Urbanization drives global socio-spatial transformation. Informality is central to this transformation, but is treated as a peripheral process on the margins of cities and economies. Informality is often associated with specific locations, overlooking the fact that it constitutes a dynamic, global process operating across spatial and temporal scales. We develop the concept of informal infrastructuring to interrogate how, through informality, people , places , processes , and politics reconfigure and build urban life. We draw together planetary and postcolonial strands of urban theory to conceptualize informal infrastructuring as a global phenomenon. To imagine informality as peripheral is to mistake marginalization with marginality.