This study explores the application of Islamic Sharia in Aceh from the perspective of legal pluralism, a theory that recognizes multiple legal systems coexisting within a society. The research employs a normative legal analysis, focusing on the integration of state law, customary law, and Islamic law. Data was collected through literature review, highlighting the successful implementation of Islamic Sharia in Aceh, where it harmonizes with state law and customary practices. The state has provided juridical legitimacy through laws and judicial institutions, while traditional institutions have been revitalized in customary law and justice. The study emphasizes that Islamic Sharia in Aceh has achieved harmonization between state, custom, and Islamic law, reflecting a strong scientific logic and cultural integration. The implementation of Islamic Sharia in Aceh is supported by legal and sociological legitimacy, and the state's recognition of its importance in the region's legal system.This study explores the application of Islamic Sharia in Aceh from the perspective of legal pluralism, a theory that recognizes multiple legal systems coexisting within a society. The research employs a normative legal analysis, focusing on the integration of state law, customary law, and Islamic law. Data was collected through literature review, highlighting the successful implementation of Islamic Sharia in Aceh, where it harmonizes with state law and customary practices. The state has provided juridical legitimacy through laws and judicial institutions, while traditional institutions have been revitalized in customary law and justice. The study emphasizes that Islamic Sharia in Aceh has achieved harmonization between state, custom, and Islamic law, reflecting a strong scientific logic and cultural integration. The implementation of Islamic Sharia in Aceh is supported by legal and sociological legitimacy, and the state's recognition of its importance in the region's legal system.