Mohammad Sadeq al-Sadr (1943? - February 19, 1999) was a prominent, moderate Iraqi Shiite cleric. In his position as a widely-respected leader of the Shiite majority in Iraq, he publicly called for government reforms and release of detained Shiite leaders. He was originally elevated to a high position among the Shia by the Baath Party following the Persian Gulf War in an attempt to find a puppet amongst the Shiites. But Al-Sadr did not play along with the Baath regime's plans, and rather used his position to call for reforms and religious freedom in public. The growth of his popularity also put him in competition with other Shiite leaders including Sayed Mohammed Baqir al-Hakim who was exiled in Iran.

He was killed under mysterious circumstances by Saddam Hussein's forces in the Iraqi city of al-Najaf at the age of 55 along with two of his sons as they drove through the town. Their car was ambushed by men, and all three occupants of the car were killed by gunfire. Popular opinion among Shiites in Iraq, as well as many international observers, holds that the Iraqi government was implicated if not directly responsible. A few journalists have reported that Saddam Hussein took credit for al-Sadr's death, poking fun at the man while in prison in late 2003.

Following the fall of Baghdad, the majority-Shiite suburb of Saddam City was unofficially but popularly renamed to Sadr City in his honor. His son, Muqtada al-Sadr, bases his claim to legitimacy upon his relationship to his father, and gains much of his support through the popularity of his father. Despite this, the true successor of Muhammad Sadeq al-Sadr is considered to be Ayatollah Kazem al-Haeri, who provides legal advice to the younger Sadr from his exile in Iran.

He was the brother of Ayatollah Muhammad Baqir al-Sadr, and the father of current Shia leader, Muqtada al-Sadr.