This study explores the harmonization of state law, customary law, and Islamic law in Aceh through the lens of legal pluralism. Indonesia recognizes multiple legal systems, including state law, customary law, Islamic law, and international law. In Aceh, Islamic sharia is part of legal pluralism, where law is viewed not only as state-made but also as a recognition of existing legal realities in a pluralistic society. The study uses legal pluralism theory to analyze how Islamic sharia has been implemented in the context of state law, customary law, and Islamic law. Findings show that Islamic sharia has been well integrated into these systems, with the state providing juridical legitimacy through laws and judicial institutions like sharia courts. Traditional institutions have also been revitalized in terms of customary law and justice. The argument emphasizes that Islamic sharia in Aceh has successfully harmonized state, customary, and Islamic law. Legal pluralism in Indonesia includes diverse judicial institutions, such as general courts, religious courts, and customary courts. Aceh, with its deep-rooted Islamic traditions, has historically practiced legal pluralism, where Islamic law and customary law coexisted. The implementation of Islamic sharia in Aceh has been influenced by historical events, including post-conflict and disaster periods. The study also discusses the challenges and developments in legal pluralism in Aceh, including the role of customary law in inheritance cases and the integration of Islamic law with customary law. The study highlights the importance of legal pluralism in achieving justice and ensuring the rights of victims. The application of Islamic sharia in Aceh reflects a harmonization between state, customary, and Islamic law, with no significant conflict between these systems. The study concludes that legal pluralism in Aceh has successfully integrated Islamic law with state and customary law, demonstrating the effectiveness of legal harmonization in a pluralistic society.This study explores the harmonization of state law, customary law, and Islamic law in Aceh through the lens of legal pluralism. Indonesia recognizes multiple legal systems, including state law, customary law, Islamic law, and international law. In Aceh, Islamic sharia is part of legal pluralism, where law is viewed not only as state-made but also as a recognition of existing legal realities in a pluralistic society. The study uses legal pluralism theory to analyze how Islamic sharia has been implemented in the context of state law, customary law, and Islamic law. Findings show that Islamic sharia has been well integrated into these systems, with the state providing juridical legitimacy through laws and judicial institutions like sharia courts. Traditional institutions have also been revitalized in terms of customary law and justice. The argument emphasizes that Islamic sharia in Aceh has successfully harmonized state, customary, and Islamic law. Legal pluralism in Indonesia includes diverse judicial institutions, such as general courts, religious courts, and customary courts. Aceh, with its deep-rooted Islamic traditions, has historically practiced legal pluralism, where Islamic law and customary law coexisted. The implementation of Islamic sharia in Aceh has been influenced by historical events, including post-conflict and disaster periods. The study also discusses the challenges and developments in legal pluralism in Aceh, including the role of customary law in inheritance cases and the integration of Islamic law with customary law. The study highlights the importance of legal pluralism in achieving justice and ensuring the rights of victims. The application of Islamic sharia in Aceh reflects a harmonization between state, customary, and Islamic law, with no significant conflict between these systems. The study concludes that legal pluralism in Aceh has successfully integrated Islamic law with state and customary law, demonstrating the effectiveness of legal harmonization in a pluralistic society.