This volume examines the substance of European Union (EU) democracy promotion by comparing it with norms of governance that other international actors promote, among them the United Nations, the United States, the Central and East European EU member states, Russia, China and non-governmental organizations. The book offers a better understanding of the EU’s democracy promotion agenda and the (in)distinctiveness of the norms diffused by the EU. Building on a common conceptual introduction, the chapters follow different theoretical approaches and research designs, and focus on a range of diverse case studies. The book concludes that, in comparison with other international actors, the EU’s conceptual approach to democracy promotion is diffuse, which in turn makes the EU a particularly flexible but also ‘technical’ democracy promoter when it comes to implementation. At the same time, there are limits to flexibility at the level of concepts and frames. This book was originally published as a special issue of the Cambridge Review of International Affairs.