100 Think Tanks to Watch 2025 is a peer-driven recognition initiative that celebrates organisations shaping ideas and driving change around the world. Built entirely on nominations from other think tanks, sector professionals, and members of the On Think Tanks community, the list highlights institutions that their peers believe have demonstrated noteworthy practices, innovative approaches, or impactful contributions in the past year.

This is not a ranking, nor is it a list of the “best” think tanks. No technical performance metrics or output-based criteria were used in the selection process. Instead, inclusion reflects the value placed on these organisations by their peers — recognition grounded in the sector’s collective knowledge, experience, and appreciation of good practice. 

At OTT, we have reflected on the limitations of traditional think tank rankings and the challenges they pose. With this initiative, our aim is different: to celebrate meaningful work, encourage collaboration, and create opportunities for shared learning within the global community. 

The list is dynamic and will evolve each year as new organisations emerge and new practices are recognised. It is organised by subregion, based on headquarters location and, where relevant, primary geographic focus, and alphabetically within each subregion. In addition, role-based tags make it easy to explore organisations with similar approaches or areas of work. 

Please keep reading to find out how to join the various spaces and services offered by OTT.