In this article, we analyze the political sources of cross-national differences in financing social protection around the world. The type of funding is not simply a technical detail but provides insights into the kinds of social contracts that underpin national social protection systems, reflecting different redistributive ambitions, conceptions of solidarity, and legitimacy among societies. Based on International Labour Organization (ILO) data, we explore to what extent past and contemporary political factors such as colonial and communist legacies as well as regime differences and war experiences account for cross-national differences in funding social protection across the globe. Our empirical evidence suggests that historically rooted political differences explain large parts of today’s highly divergent patterns in social security funding systems.