The study of Theravada Buddhism and gender has often focused on the relationship between men's and women's roles, particularly their differing ability to become fully ordained monks. Yet in Thailand, as in many parts of the world, gender is more complicated than the binary of just men and women. Scholars have noted that what it means to be a man in Thailand is often defined in terms of not being effeminate, gay, or transgender. Drawing on Thai news stories, social media comments, and ethnographic research, I explore how monastic masculinity—the way in which what it means to be an ideal monk informs notions of being an ideal man—is constructed through the assertion that effeminate gay or kathoei (transgender) individuals cannot and should not be ordained. Taking into account such broader social constructions of gender and sexuality is important to better understand the relationship between masculinity and Buddhist monasticism.