The supposedly fixed set of norms within the Association of Southeast Asian Nations (ASEAN), commonly referred to as the “ASEAN way,” is both celebrated and maligned as a key element of Southeast Asian diplomacy. In this article, we contest this orthodoxy through a practitioner-near account of ASEAN diplomatic norms in practice. We find that the “ASEAN way” is best understood as a rhetorical commonplace, a well-established topological resource that social agents use to advance and contest claims of competent diplomatic practice in the ASEAN community of practice. We build on and bridge insights from norm contestation, practice theory, and discourse literatures to develop an original framework for the study of contestation in communities of practice. Drawing from documentary evidence and 61 interviews with practitioners of ASEAN diplomacy, we illustrate our argument by examining contestation in practice in the context of the organization’s response to the Rohingya crisis and the South China Sea disputes.