To date, international law has not featured prominently in academic analyses of Buddhism. Especially absent from this small body of literature are real-life examples of Buddhist monks and laity turning to international law to resolve grievances or protect Buddhism against perceived threats to it. This article seeks to fill this void. Drawing on interview and archival sources from Sri Lanka and the United Nations, it analyzes how one particular monk from Colombo became a key agent in the interpretation and transformation of international law. By so doing, this article complements existing scholarship concerning Buddhism’s philosophical or conceptual sympathies with international legal principles and provides further empirical ballast for understanding how, when and why Buddhists turn to international law.