Network concepts are omnipresent in contemporary diagnoses (network society), management practices (network governance), social science methods (network analysis) and theories (network theory). Instigating a critical analysis of network concepts, this article explores the sources and relevance of networks in Foucault’s social theory. I argue that via Foucault we can trace network concepts back to cybernetics, a research programme that initiated a shift from ‘being’ to ‘doing’ and developed a new theory of regulation based on connectivity and codes, communication and circulation. This insight contributes to two debates: Firstly, it highlights a neglected influence on Foucault’s theory that travelled from cybernetics via structuralism and Canguilhem into his concept of power. Secondly, it suggests that network society and governance are neither a product of neoliberalism nor of technological artefacts, such as the Internet. They rather resulted from a distinct tradition of cybernetically inspired theories and practices.