This paper examines how politically connected firms shape housing supply in U.S. cities. Using new data on campaign donations to U.S. mayors and a regression discontinuity design, I present three findings. First, developers connected to the mayor sell more new housing units. Second, more sales of new housing by connected developers coincide with higher local housing supply: cities where mayors received more developer donations issue nearly 70 percent more permits for new housing units. Third, differences in mayors’ pre-existing policy stances—rather than connections to developers—is a quantitatively larger determinant of local housing supply.