| Office4: | Member of the Assembly of Experts |
| Term Start4: | 3 September 2001 |
| Term End4: | 21 February 2019 |
| Constituency4: | Qom Province |
| Term Start5: | 15 August 1983 |
| Term End5: | 22 February 1999 |
| Constituency5: | Semnan Province |
| Office6: | Member of the Guardian Council |
| Term Start6: | 17 July 1983 |
| Term End6: | 21 February 2019 |
| Appointer6: | Ruhollah Khomeini Ali Khamenei |
| Birth Date: | 13 January 1938 |
| Birth Place: | Qom, Iran |
| Death Place: | Tehran, Iran |
| Alma Mater: | Hawza Najaf |
| Party: | Society of Seminary Teachers of Qom |
Ayatollah Mohammad Momen (13 January 1938 – 21 February 2019)[1] was a Faqih (a cleric qualified to judge based on Islamic law) and a very influential member of the Guardian Council of the Islamic Republic of Iran.
He simultaneously sat on the Expediency Discernment Council and the Assembly of Experts, representing the Islamic holy city of Qom in the latter and winning in the 2006 Iranian Assembly of Experts election. He gained a very large percentage of the vote.[2] His opponent, Ayatollah Mohammad Taqi Mesbah-Yazdi, was a strong supporter and spiritual mentor of President Mahmoud Ahmadinejad, and his victory has been interpreted by some as a sign of dissatisfaction with Ahmedinejad's policies. Because of his political influence in the government, Siyasat, a conservative weekly periodical, had been touted, along with the hard-line conservative Ayatollah Morteza Moghtadai, to be a possible replacement for Judiciary Chief Ayatollah Mohammad Yazdi.[3]
He was a moderate conservative,[4] and was considered to be an excellent student of the Qur'an. He was a notable figure among fundamentalists in Iran. Some considered him to be more of a theologian than a politician.