The Buddhist nationalist movements that emerged during the political and economic liberalization of the second parliamentarian period (2011–2021) in Burma/Myanmar provide unique material for the study of monastic authority. The aim of this article is to examine two overlapping dynamics regarding how monastic authority is established and undermined. As for the first dynamic, the article examines three strategies in Buddhist nationalist sermons aiming to provide legitimacy for the nationalist monks. The second dynamic is a political outgroup criticism that became more common during the period in question. The article makes a distinction between generic monastic authority, which is the fundamental one, and nationalist monastic authority, as they are legitimized and established in different ways. Finally, the article argues that recognition of monastic authority by laypeople is based not merely on trust and respect but tends to be a more complex process.