Iranian-born cleric who, as a grand ayatollah based in the holy city of Al-Najaf (Najaf, Al-), Iraq, was the spiritual leader of millions of Shīʿite Muslims.

Khoei studied Persian poetry and religion as a child. At age 13 he was sent to study Islamic law ( Sharīʿah) at Al-Najaf, where he remained and became one of the most important Shīʿite clerics of his day, attaining the status of marjaʿ al-taqlīd (Arabic: “source of emulation”) in 1970 and ministering to Shīʿite communities both in Iraq and throughout the world. Khoei was mentor to many of the most important clerics of the last quarter of the 20th century, including Muḥammad Bāqir al-Ṣadr of Iraq and Mūsā al-Ṣadr and Muḥammad Ḥusayn Faḍlallāh of Lebanon. He established an international charitable foundation (Al-Khoei Benevolent Foundation) and wrote more than 90 books on Shīʿite religion, including a commentary on the Qurʾān, Al-Bayān fī Tafsīr al-Qurʾān (“The Elucidation of the Exegesis of the Qurʾān”). Although he openly criticized the regime of Mohammad Reza Shah Pahlavi (Reza Shah Pahlavi), he refused to endorse Ayatollah Ruhollah Khomeini (Khomeini, Ruhollah) and his Islamic revolution in Iran and was widely regarded as the chief spokesman for the “quietists”—those Shīʿite clerics who believed that the religious class should avoid political activism. He also refused to take sides in the Iran-Iraq War (1980–88), and after an unsuccessful Shīʿite uprising against the Iraqi regime in the wake of the Persian Gulf War (1990–91), the Iraqi regime placed Khoei under house arrest. The Iraqi government refused to allow a large public funeral for the cleric, but the governments of both Iran and Iraq declared an official three-day period of mourning following his death.