This study examines the role of the Regional Inspectorate of South Papua Province in implementing preventive oversight as a strategic measure to combat corruption from the early stages of institutional development. As a newly established autonomous region, the reinforcement of internal control systems is critical to building transparent and corruption-free governance structures. The findings reveal that the effectiveness of corruption prevention remains hindered by structural challenges, such as a limited number of certified auditors, underdeveloped digital infrastructure, and insufficient budget support. Moreover, bureaucratic resistance and weak inter-institutional coordination have further constrained the impact of oversight functions. The study recommends a transformation of institutional capacity and bureaucratic culture through the enhancement of inspectorate competencies, the adoption of risk-based audits, and stronger political and regulatory backing. With the right strategies, preventive oversight can serve as the frontline defense in promoting public accountability and integrity in South Papua. This research contributes a novel perspective by focusing on the preventive supervision practices within a newly autonomous province, using a contextualized evaluative framework grounded in the principles of good governance. The findings provide both theoretical insights and practical recommendations for strengthening internal control mechanisms in regional bureaucracies, particularly those in transition.