At first glance, social justice seems to be absent in the history of European integration, which ultimately led to the European Union of our own times. This chapter arrives at a different conclusion. It focuses on the period from the 1950s until the Maastricht Treaty and argues that European integration was not simply the neoliberal project it is often described as. Already the Schuman Declaration of 1950 called for a ‘solidarité de fait’. While social justice never became a key concept defining the policies of the European Community, the EC started to develop a distinct approach to social issues since the 1950s. It primarily sought social progress through economic cooperation, not through redistributive social policy. Moreover, the EC served as a platform for the exchange of experts, complementing the role of national actors, transnational forums, and other international organizations such as the International Labour Organization. But it also started developing a highly diverse set of policy instruments with deep implications for social justice. These policies remained patchy. They gained importance only incrementally and never seemed to be driven by an overall logic. Even if the EC was a hidden actor on questions of social justice, it clearly mattered.