There is scant systematic empirical evidence on what explains variation in academic freedom. Making use of a new indicator and panel data covering 64 countries 1960–2017, we investigate how de facto academic freedom is affected by, in particular, political institutions. We find that moving to electoral democracy is positive, as is moving to electoral autocracy from other autocratic systems, suggesting the importance of elections. Communism has a strongly detrimental effect. Legislatures that are bicameral are associated with more academic freedom, while legislatures that become more diverse and more ideologically to the right also seem to stimulate this type of freedom. Presidentialism and coups do not appear to matter much, while more proportional electoral systems strengthen academic freedom. More judicial accountability stimulates academic freedom, and richer countries experience more of it. The results suggest that the political sphere exerts a clear but complex influence on the degree to which scholarly activities are free.