Papua’s Special Autonomy framework was designed to promote democratic, participatory, accountable, and welfare-oriented governance, particularly for Indigenous Papuans. However, its implementation in Jayapura City has not yet produced substantive public participation due to ineffective regulatory implementation, limited institutional and human resource capacity, inadequate legal literacy, and weak stakeholder coordination and assistance. This study analyzes the role of legal strengthening in optimizing public participation and formulates a legal strengthening strategy for Special Autonomy governance in Jayapura City. Using a qualitative approach grounded in a pragmatist paradigm, the study integrates Administrative Law and the Theory of Planned Behavior. Primary data were obtained through an in-depth interview with a member of the Papua Special Autonomy Development Acceleration Steering Committee, while secondary data came from legislation, policy documents, and scholarly literature. Data were analyzed using the interactive model of Miles, Huberman, and Saldaña. The findings show that participatory channels exist through the Papuan People’s Assembly, Indigenous forums, women’s and religious organizations, and political representation, but their influence on decision-making remains limited. The study proposes a collaborative governance-based legal strengthening model integrating regulatory reform, institutional strengthening, human resource development, legal literacy and assistance, transparency, accountability, and stakeholder collaboration to transform procedural participation into substantive participation.