<![CDATA[There is a decline in students' religious character amidst the modernization of education, which tends to prioritize cognitive aspects over religious character formation. Furthermore, the implementation of the "hidden curriculum" in Islamic education is often viewed merely as a supplement to the formal curriculum, despite its strategic role in internalizing religious character in students. This study aims to analyze policies regarding the hidden curriculum in Islamic primary *madrasahs*, describe its implementation in fostering students' religious character, and explain its implications for that character formation. A qualitative case study approach was employed, utilizing in-depth interviews, observation, and document analysis involving *madrasah* principals, curriculum vice-principals, teachers, and the *madrasah* environment. Data analysis involved data reduction, data presentation, and conclusion drawing. The results indicate that the hidden curriculum is implemented through the cultivation of a religious culture, teacher role-modeling, implicit rules, and the integration of Islamic boarding school culture, all of which are effective in holistically shaping religious character. This implementation is realized through daily, weekly, monthly, and annual religious activities. The study finds that consistent religious habituation facilitated by reinforcement and positive social experiences successfully fosters student character traits such as discipline, responsibility, honesty, noble character religious, tolerance, spirituality, and social concern. The hidden curriculum serves not merely as a supplement to the formal curriculum but as a character-building system that operates naturally, sustainably, and integrally within the religious culture of the formal educational institution]]>
