Human rights debates neglect social rights. This paper defends one fundamentally important, but largely unacknowledged social human right. The right is both a condition for and a constitutive part of a minimally decent human life. Indeed, protection of this right is necessary to secure many less controversial human rights. The right in question is the human right against social deprivation. In this context, ‘social deprivation’ refers not to poverty, but to genuine, interpersonal, social deprivation as a persisting lack of minimally adequate opportunities for decent human contact and social inclusion. Such deprivation is endured not only in arenas of institutional segregation by prisoners and patients held in long-term solitary confinement and quarantine, but also by persons who suffer less organised forms of persistent social deprivation. The human right against social deprivation can be fleshed out both as a civil and political right and as a socio-economic right. The defence for it faces objections familiar to human rights theory such as undue burdensomeness, unclaimability, and infeasibility, as well as some less familiar objections such as illiberality, intolerability, and ideals of the family. All of these objections can be answered.