This article develops a theoretical and empirical evaluation of the overlooked relationship between urbanization and political change. To accomplish this, theoretical insights from Weber, Lerner and Lipset’s political modernization thesis, and Dahl and Tufte’s analysis of size and democracy are used to assess the link between features of a nation’s urban system and changes to its political trajectory. A cross-national time-series analysis of 110 nations from 1965 to 2010, as well as the mini case study of Morocco, provides strong evidence that various dimensions of urbanization play an important role in eliciting political change in the developing world.