This chapter analyzes the adoption, development and promotion of the emerging customary international legal norm of indigenous peoples’ free, prior and informed consent (FPIC) by the Forest Stewardship Council (FSC). This case reveals how transnational business governance interactions (TBGIs) can offer an avenue to develop, import and apply elements of the powerful international discourse of human rights inside states, with the potential of strengthening domestic standards and advancing marginalized actors. It also offers insight into the influential role that can be played in these interactions by a class of non-state actor often neglected in accounts of transnational governance: the transnational indigenous peoples’ movement. Indigenous representatives leveraged FSC’s inclusive governance structures, the moral force of international human rights law, and interactions between FSC International and FSC Canada to strengthen the FPIC norm in FSC standards. This has led to the FSC’s advocacy of a strengthened and enriched version of FPIC that compares favorably with the most robust readings of FPIC by international organizations and states, situates FSC Canada at the leading edge of indigenous rights norm development in transnational governance, and opens an avenue toward a de facto requirement for ongoing indigenous consent to forestry operations in Canada.