Mahr (dowry) serves as a fundamental institution in Islamic marriage law and represents a legally recognized economic right of women, grounded in Qur’anic injunctions and Islamic Law. Despite sharing a common normative foundation, the regulation and practical enforcement of mahr vary considerably across Muslim societies, particularly those characterized by legal pluralism and differing levels of state codification. This article examines mahr as a women’s right within Islamic family law through a normative-comparative analysis of Nigeria and Indonesia. Employing doctrinal legal research and a comparative law approach, the study analyzes the concept of mahr in Islamic jurisprudence and its regulation within the respective Islamic family law frameworks of both countries. The findings reveal that both Nigeria and Indonesia recognize mahr as a mandatory obligation of the husband and the exclusive proprietary right of the wife. However, significant divergences emerge in terms of regulatory structure, institutional enforcement, and legal certainty. In Nigeria, Islamic family law operates within a plural legal system where Islamic law—predominantly influenced by the Maliki school—coexists with customary and statutory laws, resulting in fragmented enforcement and uneven protection of women’s mahr rights. By contrast, Indonesia has incorporated Islamic family law into a more unified statutory framework through Law No. 1 of 1974 on Marriage and the Compilation of Islamic Law, supported by the jurisdiction of Religious Courts, thereby providing relatively clearer mechanisms for legal enforcement, notwithstanding ongoing challenges related to customary practices and implementation. This comparative analysis demonstrates that legal codification, institutional coherence, and state involvement play a crucial role in enhancing legal certainty and strengthening the protection of women’s economic rights in marriage.