Grand Ayatollah Mohammad Hussain Fadlallah (also Sayyed Muhammad Hussein Fadl-Allāh; November 16, 1935 –  July 4, 2010) is a prominent twelver Shia cleric from a Lebanese family.

Born in Najaf, Iraq, Fadlallah studies Islam in Najaf before moving to Lebanon in 1952

In the following decades, he gives many lectures, engages in intense scholarship, writes dozens of books, founds several Islamic religious schools, and establishes the Mabarrat Association.

Through the aforementioned association, he establishes a public library, a women's cultural center, and a medical clinic.

Fadlallah is sometimes called the "spiritual mentor" of Hezbollah in the media, although this is disputed by other sources.

He is also the target of several assassination attempts, including the 1985 Beirut car bombing.

His death is followed by a huge turnout in Lebanon, visits by virtually all major political figures across the Lebanese spectrum, and statements of condolence from across the greater Middle East region; but it also leads to controversy in the west and a denunciation in Israel.