Murtaḍā b. Muḥammad Amīn al-Anṣārī (Arabic: مرتضی بن محمد امین الأنصاري, b. 1214/1800 - d. 1281/1864) known as al-Shaykh al-Ansārī and al-Shyakh al-Aʿzam was a notable Shi'a scholar in the 13th/19th century. After Muhammad Hasan al-Najafi he became the general marja' of Shi'as.
He was titled "Khatam al-fuqaha wa al-mujtahidin" (the seal of jurists and mujtahids). He was famous for being accurate and having profound thoughts. He moved principles of jurisprudence and consequently jurisprudence to a new phase through his new doctrines. His famous books, al-Rasa'il and al-Makasib, are taught to seminary students of principles of jurisprudence and jurisprudence. Most of the scholars after him, are his followers. After al-Muhaqqiq al-Hilli, al-'Allama al-Hilli, and al-Shahid al-Awwal, al-Shaykh al-Ansari is the only one whose books were taken into considerations so highly that religious scholars wrote many commentaries and glosses on his books.
Many stories are written about his God wariness and asceticism. He passed away and is buried in Najaf.
