This article analyzes the inputs and constituencies (funding, founders, trustees, and experts) of the most influential group of think tanks in Spain during the great recession (2008-2015) in order to assess how far these think tanks were connected to other interest groups providing support for neoliberal policies. The aim of the article is to advance knowledge on think tank theory and it addresses three research goals: (a) assessing how far Spanish think tanks are affected by political clientelism and financialization, (b) identifying those actors who direct Spanish think tanks and collaborate with them, and (c) assessing the think tanks’ connections with international lobbying networks. Our results show that the think tanks studied are consistently related to three types of actor—political, economic, and academic—while also maintaining strong ties with the media. In this regard, their main traits are a pluralism biased toward right and center-left stances, state and party clientelism, the financial and political instrumentalization of party tanks, and the superior ability of conservative tanks to build network coalitions.