Juan José Linz (24 December 1926 – 1 October 2013) was a Spanish sociologist and political scientist. He was Sterling Professor Emeritus of Political Science at Yale University and an honorary member of the Scientific Council at the Juan March Institute. He is best known for his theories on totalitarian and authoritarian systems of government.

Linz was born in Bonn, Germany. In addition to his work on systems of government, he did extensive research on the breakdowns of democracy and the transition back to a democratic regime. He is the author of many works on the subject, including Problems of Democratic Transition and Consolidation: Southern Europe, South America, and Post-Communist Europe (Johns Hopkins University Press, 1996, co-authored with Alfred Stepan), his seminal work Totalitarian and Authoritarian Regimes (Rienner, 2000) and his influential essay 'The Perils of Presidentialism'.

Originally a chapter in the Handbook of Political Science, this analysis develops the fundamental destinction between totalitarian and authoritarian systems. It emphasizes the personalistic, lawless, non-ideological type of authoritarian rule the author calls the sultanistic regime.