This chapter puts the focus on “who” might be (held) responsible under the UN Guiding Principles on Business and Human Rights (UNGPs). He argues that corporate responsibility under the UNGPs should be understood as an activity-based concept, according to which business models are to be made compatible with respect for human rights respect. In this light, not the legal entities, but rather business strategy, organizational processes, and managerial routines become constitutive elements of business enterprise. Such business enterprise responsibility also implies individual and collective responsibilities of certain people, who will be referred to as the “function-holders” of an enterprise, to act according to these routines and to take human rights into account when they make decisions. Against the backdrop of the French “due diligence law”, the “Loi relative au devoir de vigilance des sociétés mères et des entrprises donneuses d’ordre”, this chapter will highlight salient differences between the UNGPs’ (extra-legal) corporate responsibility to respect human rights and legal due diligence standards. This demonstration aims at revealing the breadth of challenges the law faces when it seeks transform the UNGPs’ due diligence concept into a legal norm. It will show to what extent the French law, albeit clearly inspired by the UNGPs, has poorly captured essential elements of the UNGPs’ corporate responsibility.