Despite the central role of foreign direct investment (FDI) in global economic integration, we lack explanations for why countries restrict FDI inflows. This article analyzes the sources of FDI liberalization using a comprehensive new data set of national foreign ownership restrictions spanning over 90 countries for the period 1970–2000. Analyses of this data show that democratization contributes to greater FDI openness. Democratization elevates the political influence of labor, the primary beneficiary of unrestricted FDI inflows. Democracies restrict six percent fewer of their manufacturing and service industries as compared to nondemocracies. This finding is robust to several controls for alternate explanations including economic crises, coercion, and diffusion, alternate measures of both democracy and foreign ownership restrictions, and a variety of model specifications. This article elucidates the political economy foundations of the contemporary world economy.