Using the practical empirical example of the Interpol Organization, the paper explores the relationship between transnational organization and transnational law. Pace Jessup’s pioneering work in 1956, the central questions surrounding the notion of transnational law have involved understanding the use of legal tools in an administrative grey area of global governance across a range of legal institutions. This essay demonstrates how Interpol constituted as itself a formal ‘Intergovernmental Organization’ with its own self-governing structure and explores the use of one of its most powerful legal tools: the Red Notice. As a formally constituted igo with transnational reach and legally subject to its own constituted governance processes, Interpol is an example of what Neil Walker calls ‘constitutionalism beyond the State’. A fortiori, Interpol mobilizes a range of legal tools from transnational public international law and criminal law, as well as those of its own constitutional order, in making up its organization. Following Terence C. Halliday and Gregory Shaffer, and based on this empirical case study, the essay argues that Interpol is an important constituent element in the broader ‘transnational legal order’ of global policing. The challenge for socio-legal scholarship is to reveal how the transnational legal order of which Interpol is a part, is shaped by a variety of actors using different kinds of legal instruments because the institutional patterns thereby established have consequences for future developments. The transnational legal order of global policing is a synecdoche of global governance more generally and the specific case of Interpol provides the basis of some general claims about how to understand the concept of law under transnational conditions. The essay argues that Interpol is but a small constituent element of an evolving global system of rule with law. Rule with law emphasizes that in all practical circumstances legal tools are in the hands of knowing social actors. Understood this way, law is practical politics undertaken by means of legal tools. Interpol is but one element of a vast transnational legal order that has no democratic basis and which needs to be progressively uncovered through piecemeal empirical case studies. Read against the backdrop of broad socio-legal theory, such case studies offer critical insights concerning contemporary transnational legal ordering.