This paper proposes urbanization as a determinant of government size. As people move to cities, their demand for a more de ned set of regulations, but also for basic health, education, and income standards rises. Our theoretical framework determines how the regional distribution of the population a ects government size. We test this theory on panel data of 175 countries from 1960 to 2010 and two state-level samples from Colombia and Germany. Results demonstrate a strong positive e ect from urbanization on government spending, with a 1 percent increase in the amount of urban citizens leading to a 0.2 percent rise in public expenditure. Our ndings indicate that public sectors may become more important as worldwide urbanization is progressing. This result underlines why government e ectiveness and the quality of public goods provision will be even more important in the future.