Mohammad-Ali Najafi (Persian: محمدعلی نجفی; born 13 January 1952) is an Iranian mathematician and reformist politician who was the Mayor of Tehran, serving in the post for eight months, until April 2018.

He received his Master of Science degree in mathematics with the final grade of A+ in 1976 but dropped out of PhD program in 1978 during the Iranian revolution to return to Iran.

He was a faculty member at department of mathematical sciences in Sharif University of Technology from 1984 to 1988, when he moved to government.

[11] However, Najafi resigned from his position on 30 January 2014 due to health problems, making it the first change in Rouhani's cabinet.

[12] On 21 July 2017, Najafi was the candidate with the most votes among the seven top candidates for Mayor of Tehran[13] and on 10 August 2017, unanimously elected as the new mayor by the City Council of Tehran defeating Elaheh Koulaei and Mohsen Mehralizadeh.

[16] Najafi resigned on 14 March 2018 after a video surfaced of him watching girls dancing, which offended Iranian clerics.

[17] On 28 May 2019, Najafi's second wife, Mitra Ostad, was found dead in the bathtub of her home in Sa'adat Abad's Armita Tower.

Hours later, Najafi confessed to murder by referral to police The ISNA news agency, stated that the head of the intelligence police, Alireza Lotfi, said about the details of Mr. Najafi's confession: "In his initial conversations, he stated that this action was carried out due to psychological pressures and family problems.