This innovative book explores think tanks from the perspective of critical policy studies, showcasing how knowledge, power and politics intersect with the ways in which think tanks intervene in public policy. Expert contributors offer multidisciplinary analyses of the history of policy advice and expertise and highlight recent examples of how think tanks navigate public debates, political arenas and the backstage of decision-making. They provide an overview of historical developments in the emergence and evolution of think tanks and consider how current think tanks produce policy narratives and exercise influence through the power of ideas. Focusing on institutional structures and social forces, chapters explain how national and transnational think tank landscapes are organized and how think tanks shape knowledge production infrastructure in different governance contexts. The book concludes that evaluating this infrastructure is crucial for ensuring that policy discourse serves collective interests and inclusive policy learning in diverse democratic polities. This book's evaluation of the impact of think tanks on expertise, democracy and social justice, while utilizing rigorous empirical research, will be useful for scholars and students of public policy, political theory and public administration and management. It will also be beneficial for think tankers and policy analysts.