Ismail as-Sadr (born 1842 - died 1919–1920) was a Lebanese Grand Ayatollah, a title which is used in Iran and Iraq referring to a Twelver Shi'a scholar who is a fully qualified mujtahid who asserts authority over peers and followers by virtue of sufficient study and achievement of the level of necessary competency needed to obtain permission (ijāza) to practice ijtihad.

Life and family

Sayyid Ismail as-Sadr is the grandfather of the Sadr family. He is the first to be known with the last name of as-Sadr after his father Sadr ad-Din ibn Salih, whose ancestors had been from the Jabal Amel in Lebanon. Ismail As-Sadr was born in Isfahan, Iran. He was the youngest of five brothers all of whom became scholars of Shia Islam. He had four sons: He resided in Najaf, Iraq, and became the sole marja until his death in 1338 A.H. (c. 1919–1920).