This study aims to analyze the positivization of Islamic law within Iran’s judicial system, particularly through constitutional, institutional, and legislative mechanisms. It employs library research with a normative juridical approach. The research data were obtained from the Constitution of the Islamic Republic of Iran, legislation, books, scholarly journals, and other relevant literature. The data were analyzed descriptively and analytically using the theory of Islamic law positivization and a legal system perspective. The findings indicate that the positivization of Islamic law in Iran operates through three main mechanisms: constitutionalization, institutionalization, and juridification. Constitutionalization establishes the formal position of Islamic principles within the constitution, institutionalization is reflected in the role of state institutions in supervising and implementing the law, and juridification involves incorporating Islamic legal norms into binding legislation. These processes are evident in the authority of the Guardian Council, the structure of judicial institutions, and the application of law in the settlement of legal disputes, particularly in family law and personal status matters. Furthermore, Islamic legal sources may still be used in certain circumstances when written legislation does not explicitly regulate a case. Nevertheless, Iran’s judicial system continues to face challenges concerning judicial transparency and independence. This study concludes that the positivization of Islamic law in Iran constitutes a process of institutionalizing Islamic norms through constitutional and state mechanisms, thereby giving them formal legal status and binding force as part of the national legal system.