This project grew out of the never ending requests I receive from journalists, scholars and government officials to provide a list of the leading think tanks in a particular country or region of the world. Last year I launched a pilot project that was designed to identify some of the leading think tanks in the world in an attempt to answer these inquiries in a more systematic fashion. The report that follows summarizes the findings of this pilot project and provides lists of what might be called the “go to think tanks” in every region of the world. 228 institutions were nominated by their peers and are public policy research, analysis and engagement organizations that have become recognized nationally, regionally and globally for producing rigorous and relevant research, publications and programs. While I have done my best to be balanced and systematic in my approach to identifying the leading think tanks in the world much more work needs to be done to improve the selection process. I, therefore, view this report as a starting point and encourage your comments and suggestions for how I might improve the selection process. Additionally, it is also worth noting that the inclusion of an institution in the universe of leading think tanks does not indicate a seal of approval or endorsement for the institution, its publications or programs. Likewise a failure to be nominated does not necessarily indicate a lack of a quality and effectiveness or poor performance. There are 5080 think tanks around the world that are doing exceptional work to help bridge the gap between knowledge and policy. This report is simply an effort to highlight some of the leading think tanks around the world.