At the United Nations (UN), the early years of the post-Cold War era were marked by a historically novel sense of urgency to render governing practices in development cooperation and humanitarian affairs more ‘human’, ‘people-’ and ‘rights’-centred. Since then, the UN ‘Human Rights-Based Approach’ (HRBA) has become widely accepted as an authoritative methodology for grasping the practical implications of rights language. This paper examines the politics of the HRBA by exploring how it ‘fixes’ the multifaceted, normatively charged and elusive object of ‘human rights’ and renders it actionable for UN agencies. It contributes to recent theorizing on knowledge in IR and ties in with critical human rights scholarship by developing a post-foundational reading of human rights and the HRBA that frontloads constitutive power and politicizes ontology. Through an in-depth reconstruction of UN knowledge production on the HRBA, I find that it excludes concerns with international power relations and depoliticizes inequality through a narrow focus on lacking subject capacities. Moreover, I illustrate that the HRBA operates according to dichotomous spatial metaphors and implicit hierarchies that locate UN agencies ‘above’ the subjects and settings they interact with, both normatively and epistemically. The paper contributes to the critical study of human rights by excavating the ambiguous power effects at work in rights-based UN methodologies. Objets multiples et solutions ontiques : les droits de l’homme et les politiques « oubliées » de l’approche fondée sur les droits de l’homme des Nation unies.