The background of the research stems from the urgency of religious moderation as the foundation for maintaining national integrity amidst Indonesia’s diversity. The objectives of the research are to describe the value of religious moderation in the Islamic Religious Education textbook for Senior High School of Grade X, to test its suitability with the Wasaţiyyah perspective of M. Quarish Shihab, and to identify dominant and less accommodated values. The research method is content analysis with a qualitative approach. The data were taken from a analysis of text book of Islamic Religious Education textbook for Senior High School of Grade X in Merdeka Curriculum, then analyzed using M. Quraish Shihab’s Wasaţiyyah parameters which emphasize justice, balance, tolerance, and deliberation. The research indicates that the Grade X Islamic Religious and Character Education textbook successfully integrates religious moderation values across faith, worship, morals, Islamic history, and nationality. Dominant values include tolerance, justice, and balance, whereas local cultural accommodation, concrete anti-violence examples, and deliberative practice remain underrepresented. Unlike previous studies that broadly evaluate textbook alignment with general moderation frameworks, this study highlights specific structural gaps in practical application within textbook discourse. Theoretically, these findings refine M. Quraish Shihab’s Wasaţiyyah framework by demonstrating that textbook moderation cannot rely solely on theoretical values like tolerance and balance, but must actively operationalize contextual and participatory elements such as local cultural integration and deliberation to foster true student agency. Overall, while the textbook aligns with core Wasaṭiyyah principles, addressing these gaps is essential for its role as a strategic tool in shaping moderate student character.