Neo-liberalism has become one of the boom concepts of our time. From its original reference point as a descriptor of the economics of the ‘Chicago School’ or authors such as Friedrich von Hayek, neo-liberalism has become an all-purpose concept, explanatory device and basis for social critique. This presentation evaluates Michel Foucault’s 1978–79 lectures, published as The Birth of Biopolitics, to consider how he used the term neo-liberalism, and how this equates with its current uses in critical social and cultural theory. It will be argued that Foucault did not understand neo-liberalism as a dominant ideology in these lectures, but rather as marking a point of inflection in the historical evolution of liberal political philosophies of government. It will also be argued that his interpretation of neo-liberalism was more nuanced and more comparative than more recent contributions. The article points towards an attempt to theorize comparative historical models of liberal capitalism