Jean Meslier, a largely forgotten figure of the history of political thought, is a radical thinker of the Enlightenment, and one who best illustrates Israel’s thesis about the period. This article, which proposes to set Meslier’s work in his intellectual context, will show just how radical this Catholic priest really was. It details the intellectual journey in Meslier’s works leading to the affirmation of his own atheism and shows how this atheism then sets the stage for the development of a proto-utilitarian doctrine. This doctrine then has consequences for political thought more widely. Against the dominant reading in the literature, which portrays Meslier as an early communist thinker, this article shows that he is best understood as a radical republican thinker. This further helps nuance the Israel’s Enlightenment thesis, by showing how republicanism (as opposed to a theory of ‘democracy’) is a better fit for the works of some radical thinkers of the period. Keywords: Jean Meslier, 18th-Century Atheism, Radical Republicanism, Utilitarism, Enlightenment