Governments around the world are looking for ways to nurture innovative businesses, as a way of solving some of their most urgent economic and societal challenges. Many seek to do this by setting up national innovation agencies: institutions that provide financial and other support to catalyse or drive private sector innovation. Yet we still know relatively little about the range of approaches that these agencies take, what programmes and instruments are likely to work best in a given context, and how to assess their long-term impact. We have been investigating these questions by studying a diverse group selection of innovation agencies in ten different countries. Our aim has been to improve understanding of the range of existing institutional models and to learn more about their design, evolution and effectiveness. In doing so, we have developed a broad framework to help policymakers think about the set of choices and options they face in the design and management of an innovation agency. This report is the most comprehensive comparative study of innovation agencies that we know of to date. However, we are keen to develop this analysis through further collaboration with policymakers and experts around the world. Please do get in touch with comments and suggestions.