Objective: This study aims to analyze how leadership hegemony shapes organizational culture through power relations within an Islamic boarding school (pesantren), with particular attention to the mechanisms through which leadership authority is legitimized and reproduced. Methods: A qualitative case study was employed at Pondok Pesantren Al-Azhar Muncar, Banyuwangi. Data were collected through in-depth interviews, participant observation, and document analysis involving key organizational actors. Data were analyzed using an interpretive-critical approach to examine leadership practices, organizational communication, power relations, and the reproduction of institutional values. Results: The findings indicate that the hegemonic leadership of KH. Abdillah As’ad shapes organizational culture through institutional regulations, spiritual role modeling, symbolic authority, and intensive internalization of Islamic values. The articulation of religious charisma with formal organizational authority produces a culture of obedience (sami'na wa atha'na), organizational loyalty, and institutional legitimacy. These mechanisms enable leadership values to become embedded in everyday organizational practices and contribute to the continuity of institutional identity and value transmission. Novelty: This study extends organizational culture theory by demonstrating that leadership hegemony in pesantren operates through the integration of symbolic, spiritual, and structural power, positioning leadership not merely as a source of authority but as a mechanism for the continuous production, legitimization, and reproduction of organizational culture.