Private international law doctrines are often portrayed as natural, largely immutable, boundaries on local public agency in a transnational private world. Challenging this problematic conception requires a reimagining of the field, not only as a species of public law or an instrument of governance, but as a constitutional phenomenon. This paper investigates what such a ‘constitution of the conflict of laws’ could look like. Two features are given special emphasis. First: the idea of the conflict of laws as an independent source of constitutionalist normativity, rather than as a mere passive receptacle for constraints imposed by classical, liberal, constitutional law. And second: the possibility of a local, ‘outward-looking’ form of conflicts constitutionalism to complement more familiar, inwardly focused, federalist conceptions.