Ayatollah Mohammad Taghi Mesbah Yazdi (Persian: محمد تقی مصباح یزدی; born 31 January 1934) is an Iranian Twelver Shi'i cleric. He is also a member of Iran's Assembly of Experts, the body responsible for choosing the Supreme Leader, where he heads a minority faction. He has been called "the most conservative" and the most "powerful" clerical oligarch" in Iran's leading center of religious learning, the city of Qom.
In Qum, from 1952 to 1960, he participated in the courses taught by Imam Khomeini and Muhammad Husayn Tabataba'i. He also attended, for approximately fifteen years, Mohammad-Taqi Bahjat Foumani.
Mesbah Yazdi advocates Islamic philosophy and in particular Sadra Mutahillin's transcendent school of philosophy (Hikmat-e Muta`aliya). He believes Iranian are moving away from religion and values of Islamic revolution and opposes democratic rule of western country and the west-oriented reform movement.
Mesbah Yazdi completed his primary and secondary education in Yazd, and then moved to Qom, where he continued his education in fiqh (Islamic Jurisprudence). He studied works of Avicenna and Mulla Sadra. In the 1950s he joined pro-Khomeini students in Qom. His teachers included prominent figures such as Ayatollah Khomeini and Ayatollah Mohammad Taghi Bahjat Foumani. He was also among the students of Ayatollah Allameh Tabatabaei, the author of Tafsir al-Mizan, the influential shi'a exegesis of Quran. He graduated in 1960. Before the Islamic revolution, he assisted the other clerics, i.e., Mohammad Beheshti and Ali Akbar Hashemi Rafsanjani, in publishing two journals called "Mission of Prophet Muhammad" and "Revenge", while he was responsible for all the publishing activities in the latter.