Rousseau's relationship to the phenomenon of modern nationalism is a consistent theme of political theory and the history of ideas. This article argues that Rousseau's thought can be seen as providing the foundation for nationalism even if he would not have endorsed it. That Rousseau's thought bears this relationship to nationalism can be seen by reexamining his argument through the lens of Benedict Anderson's concept of nations as imagined communities. Rousseau's account of political psychology, sovereignty, and the proper limits of the nation provide the core of the analysis of this question.