This introduction argues that “Buddhist masculinity” in and in relation to Sri Lanka since the late nineteenth century (c. 1880) is not a fixed identity but a shifting set of expectations about who counts as an “ideal” man and how masculinity becomes attached to Buddhism, nationhood, class, caste, and authority. It situates the study in colonial and anti-colonial struggles over manliness, showing how British ideals of discipline and rationality were both emulated and reworked through Buddhist reform, education, and public narration, and why masculinity often remains an unmarked norm even when scholarship centres on men. The introduction also outlines the book’s sources and method—digitised archives and periodicals, school materials and fieldwork, translation work, and interviews with alumni—read through feminist and queer approaches to gendered power. It closes by mapping how the chapters develop the argument across monkhood, elite schooling, mission and charisma, and kinship networks to offer a wider analysis of Buddhism and masculinity in Sri Lanka and beyond.