This paper uses Michel Foucault’s lectures on biopolitics as a starting point for thinking historically about neoliberalism. Foucault’s lectures offer a rich and detailed account of the emergence of neoliberalism, but this account is far from complete. This paper addresses some of the blind-spots in Foucault’s lectures by focusing on the space between the decline of classical liberalism at the end of the 19th century and the subsequent attempt to develop a ‘positive’ or ‘ordo’ liberalism in post-war Germany. The primary concern of this paper is to chart the emergence of a new or neo- liberalism in the writings of Ludwig von Mises and Friedrich von Hayek through the 1920s and 1930s. These writings, which are barely considered by Foucault, are important as they redefine the liberal project against the political economy of the late 19th century and, in particular, against the threat of socialism. In conclusion, it is argued that by returning to the work of Mises and Hayek it is possible to develop a critical sociology of neoliberalism, one that not only engages with the writings of these two thinkers but which also exposes the fracture lines that exist within the neoliberal project, and reconsiders the political positions that neoliberalism initially sought to reject.