The advance of neo-liberal governmentality is one of the defining features of contemporary developments in public policy and administration. In particular, public policies that seek to promote socially desirable behaviour have become the stock in trade of democratic governments across the globe. Nonetheless, in recent years, these developments have taken a more pervasive “behavioural” turn, especially in the Anglophone world. As governments of all ideological hues have come to recognise the intractability of social “problems”, so they have moved away from conventional institutional and organizational solutions to “what works” in favour of cognitive approaches that seek to shape people’s lifestyle choices rather than the social environment in which they live. Evolving out of the use of social marketing techniques associated with New Public Management, and drawing upon the theories of behavioural economics the cognitive tools of the new “persuasive state” have grown apace. This paper focuses on the creeping development of behavioural governance in the UK. The Prime Minster, David Cameron, established a Behavioural Insight Team, which in partnership with the policy think-tank, the Institute for Government, has been examining ways in which behavioural economics can be applied to social problems. Thus, the role of public policy, now is not just about taking control of the levers of state – financial instruments, institutional reform and alternative service delivery models. It is also explicitly about micro-policy mechanisms which are used to elicit changes in the psychological aspirations of the public. In this paper we introduce the political, organisational and intellectual context of the behavioural turn in governance, examining how it represents a new stage in the project of neo-liberal governmentality. The most valuable and insightful intellectual response to these developments can therefore be gained by examining the growing reach of deep behavioural governance through the lens of Michel Foucault’s work on the political technology of individuals. At the same time, consideration of behavioural governance is an ideal opportunity to further explore, and extend the Foucauldian notion of governmentality.