The current framework and discourse of “Business and Human Rights” (B&HR) focuses mainly on the universal level. In contrast, this contribution asks how regional human rights systems respond to the problem of corporate accountability in general, and to the B&HR framework in particular. On the basis of a regional comparison, the contribution argues for a contextualized, functional doctrine of direct corporate obligations under international law. This doctrine is nascent in regional human rights law, especially in the case law of the Inter-American system. It is best explained, justified and limited by a functional theory of human rights that determines corporate obligations by reference to the functions human rights per-form in concrete political contexts. To elaborate this argument, the article first surveys the regional contexts and responses to the B&HR framework in the European, Inter-American and African human rights systems. In s second step, it turns to a systematic in-depth compar-ison of the regional approaches to corporate accountability, and elaborates its own theory of direct corporate obligations based on a contextual-functionalist comparison.