Policy institutes, or think tanks, are becoming increasingly ubiquitous in our societies. In this article, we conceptualize think tanks explicitly as a civil society phenomenon, linking the proliferation of this relatively new type of actor to the transformation of civil society structures and of systems of interest representation. Using the case of Sweden as an illustration, we argue that the recent decades' rise of think tanks in institutional settings outside of the USA can only be understood if we take into account the particular features and institutional policy access opportunities of the domestic civil society in each national case, and that think tanks should be analytically understood as the allies of, rather than competitors to, the older, established forces in civil society.