From the 3rd to the 7th centuries AH, Shiʿi polities relied on educational endowments to establish a sustainable network of madrasas, dār al‑ʿilm institutions, and libraries, thereby organizing the cultural foundations of their authority. Using a descriptive–analytical method and drawing on historical sources, this study examines the role of these endowments in providing cultural legitimacy for Shiʿi polities. The analysis is based on the theoretical framework of Hamid Algar, which views waqf as a cultural mechanism for the production and transmission of religious knowledge. The findings indicate that educational endowments operated through five interconnected functional levels: the consolidation of scholarly institutions, the production and reproduction of Shiʿi knowledge, the expansion of religious identity, the training and organization of elites, and the linkage of these elites to structures of power. These functions enabled scholarly institutions supported by waqf to become arenas for the formation of intellectual authority and the strengthening of official religious discourse. Thus, educational waqf extended beyond mere financial support and functioned as an effective instrument for institutionalizing the cultural and ideological legitimacy of Shiʿi polities a conclusion that fully aligns with theories of waqf, education, and legitimacy in the cultural polities of Shiʿi governments.