This chapter is the first examination the world’s newest international court—the Unified Patent Court (UPC)—from the perspective of international law. Identifying the institutional tensions inherent in its architecture due to the close links to the European Court of Justice and national courts as well as its origins in the European patent law, the chapter elaborates the essential implications arising for the UPC by virtue of it being an international court and international law being its governing law. Drawing on the literatures on international regime interplay, functions and authority of international courts and business and human rights, as well as the experience of the investor-state dispute settlement, the chapter elaborates the salient interpretative choices that the UPC will need to make that will not only determine its day-to-day operation and case outcomes, but also the public perceptions of its authority and legitimacy. The chapter argues that if recent international legal scholarship and practice suggest anything, the UPC will be best served by an integrative approach to (its) international law—especially given patent law’s significant distributive effects.