This comprehensive Handbook examines the role of political opposition across different political systems. Contributors draw on a series of in-depth case studies, including specific chapters on country-cases to explore the impact of opposition within democracies, anocracies (or hybrid regimes), and autocracies. Leading experts explore political opposition through a theoretical and comparative perspective, identifying a common analytic framework that can be applied across regime types. They assess the many forms political opposition can take, from opposition parties and interest groups to mass protests and violent action. The Handbook examines why particular modes of opposition manifest, while empirical chapters focus on the diversity and commonalities in opposition politics across the world, using a broad range of examples from Africa, Asia, Europe, and North America. The Handbook builds on several literatures in the sub-discipline of comparative politics, ultimately shedding light on the dynamics, dimensions and constraints of political opposition. Providing insight into the theory and practice of opposition politics, this expansive Handbook will greatly benefit scholars and students of comparative political science, public policy, and European and international politics.