This research examines the factors that shape the happiness of cities, whereas much of the existent literature has focused on the happiness of nations. It is argued that in addition to income, which has been found to shape national-level happiness, human capital levels will play an important role in the happiness of cities. Metropolitan-level data from the 2009 Gallup–Healthways Survey are used to examine the effects of human capital on city happiness, controlling for other factors. The findings suggest that human capital plays the central role in the happiness of cities, outperforming income and every other variable.