| Honorific Suffix: | al-Harithi |
| Ziyad ibn Ubayd Allah زياد بن عبيد الله | |
| Term Start: | 750 |
| Term End: | 758 |
| Death Date: | c. 760s |
| Death Place: | Abbasid Caliphate |
| Father: | Ubayd Allah ibn Abd Allah al-Harithi |
| Relations: | Rayta bint Ubayd Allah (sister) |
Ziyad ibn Ubayd Allah al-Harithi (Arabic: زياد بن عبيد الله الحارثي) (full name Ziyad ibn Ubayd Allah ibn Abd Allah ibn Abd al-Madan al-Harithi) was an eighth century Abbasid governor of Medina and Mecca from 750 to 758 for the Abbasid Caliphate. He was the second Abbasid Caliphal governor of Medina and Mecca.
Ziyad was the son of Ubayd Allah ibn Abd Allah ibn Abd al-Madan al-Harithi. His sister, Rayta bint Ubayd Allah was married to Muhammad ibn Ali al-Hashimi who was the father of the first Abbasid caliph al-Saffah.
Al-Saffah appointed his paternal uncle, Dawud ibn Ali al-Hashimi[1] as the first governor of Medina and Mecca in 750, however he died in office that same year. Al-Saffah then appointed Ziyad ibn Ubayd Allah, his maternal uncle[2] as governor in 750. He remained in the office throughout the reign of his nephew al-Saffah.
He was dismissed by al-Mansur (brother and successor of al-Saffah) in 758. Muhammad ibn Khalid ibn Abd Allah al-Qasri was appointed by the caliph al-Mansur.[3]