This chapter examines private transnational law, which is argued to be a prominent form of transnational authority in the global political economy today. It approaches private transnational governance from the vantage points of international relations theory and international legal theory, arguing that neither captures the ontological significance of transnational corporations and elites as agents of transnational governance. The chapter draws upon critical political economy to advance a praxis conception of transnational law that better articulates the importance of these private sources of power and authority in the contemporary global political economy and opens up space for more progressive governance.