The European Union (EU) has experienced an unprecedented economic and financial crisis since 2007, the effects of which form the object of analysis in this Special Issue. In particular, it addresses the questions of whether and how the crisis has served as an obstacle or an opportunity for further integration. It concentrates on two broad types of implications for the EU that are central elements of theories on integration and policy and public opinion change. First, the crisis has triggered events of proposed and actual change of policies and institutions. Second, the crisis and the EU’s response to it have had an impact on how citizens perceive the EU and its democratic legitimacy. Based on the contributions by scholars of European integration, this Special Issue concludes that, at least in the short run, the crisis has (overall) created an opportunity structure for European integration rather than an obstacle. At the same time, the contributions show the need for further research on the nexus of public opinion and politicization on the one side and institutional and policy change on the other.