Unifying theoretical insights with empirical phenomena, the Elgar Encyclopedia of European Union Public Policy begins by engaging with the multi-level structure of the EU’s polity and identifies how this affects public policy, considering the role of various non-state actors in EU policymaking, and the concepts of Europeanization and policy diffusion. Offering a theoretical introduction to policy integration, it examines intergovernmentalism, neofunctionalism, and postfunctionalism, alongside an innovative analysis of policy styles and the effects of recent crises on EU public policy, including COVID-19 and populism. Chapters conclude by reflecting on policy implementation and dynamics, and the impact of feedback on public policies and institutions.