Umm Muḥammad bint Ṣāliḥ (Arabic: أم محمد بنت صالح) was an Abbasid princess, niece of third Abbasid caliph al-Mahdi and wife of caliph Harun al-Rashid.

Her full name was Umm Muhammad bint Salih al-Miskin ibn Abdallah al-Mansur.

Her grandmother was a concubine Qali-al Farrashah.^[1] She was a Greek, and was the mother of Al-Mansur's son Salih al-Miskin.^[1] Her father, Salih al-Miskin was one of the youngest sons of caliph Al-Mansur.

Umm Muhammad was the wife Abbasid caliph Harun al-Rashid. He was also her half-cousin.

Umm Muhammad was the daughter of Salih al-Miskin and Umm Abdullah, the daughter of Isa ibn Ali. They married in November-December 803 in Al-Raqqah. She had been formerly been married to Ibrahim ibn al-Mahdi, who had repudiated her.^[2]

Her first husband Ibrahim was the half-brother of Harun al-Rashid. She married him in early 780s however, just a few years later Ibrahim separated from her. After her formal divorce from her first husband, Caliph Harun al-Rashid married her.

Umm Muhammad became the second wife of Harun al-Rashid from Abbasid house. His first wife Zubaidah bint Ja'far was also an Abbasid princess and granddaughter of al-Mansur.

She spent most her life after marriage with Al-Rashid at the Caliphal palace along with al-Rashid's other wives. She died in 810s.

Umm Muhammad was related to Abbasid house both paternally and maternally. She was contemporary and related to several Abbasid caliphs, prince and princesses.