Islamic jurisprudence has long constituted a fundamental normative foundation for regulating economic and commercial relations within the legal system of the Islamic Republic of Iran. Nevertheless, the increasing complexity of the modern economy—particularly in financial markets and banking systems—raises a critical question as to whether Islamic jurisprudence can move beyond abstract rulings and function effectively as a framework for institutional regulation and economic governance. This study aims to examine the capacity of Islamic jurisprudence to regulate contemporary economic and commercial relations, with a specific focus on Iran’s financial and banking markets. Employing a descriptive–analytical methodology, the research draws upon conceptual analysis of Islamic economic jurisprudential principles, examination of legal and banking regulations, and a case study of Iran’s financial system. The findings indicate that the principal challenge facing Iran’s economic system is not the absence of jurisprudential norms, but rather the gap between legislative jurisprudence and executive jurisprudence. In practice, many financial instruments and banking contracts, despite their formal compliance with Islamic legal forms, suffer from functional formalism and fail to achieve the justice-oriented objectives of Sharia. The study demonstrates that core jurisprudential principles—such as economic justice, the no-harm rule (lā ḍarar), mutual consent, prohibition of usury (ribā), and avoidance of excessive uncertainty (gharar)—can, through a functional and institutional reinterpretation, be transformed into operational standards for economic regulation. Accordingly, the paper proposes a five-layered model of fiqh-based economic regulation that establishes a coherent link from jurisprudential principles to legislation, regulatory institutions, Sharia supervision, and practical implementation. This model provides a pathway for transitioning from formalistic jurisprudence toward jurisprudence-based economic governance, thereby enhancing transparency, efficiency, and justice in Iran’s contemporary economic and commercial relations.