Internalizing religious moderation values through the hidden curriculum in Islamic boarding schools refers to an indirect process in which religious moderation values are not explicitly taught to students through norms, habits, and culture observed and lived in the pesantren environment. In the context of Islamic boarding schools, hidden curriculum refers to the non-academic aspects of the learning experience, which are not explicitly taught through the official curriculum but are absorbed through daily experiences and social interactions. The internalization of religious moderation values through the hidden curriculum in pesantren shows how values such as tolerance, peace, inter-religious cooperation, and a moderate attitude in approaching differences in religious beliefs are reflected in the daily life of pesantren. The link between the hidden curriculum and the internalization of religious moderation values lies in the indirect influence exerted by norms, values, and culture that influence the educational environment. The hidden curriculum includes all aspects of teaching and learning that are not explicitly listed in the formal curriculum but still significantly impact the formation of student character, attitudes, and values. In religious moderation, this refers to internalizing values that create a moderate, tolerant, and open attitude toward religious differences.