Abdallah ibn Tahir al-Khurasani
| Abdallah ibn Tahir | |
|---|---|
| Governor of Khurasan | |
| In office 828–845 | |
| Monarchs | Al-Ma'mun, Al-Mu'tasim, Al-Wathiq | 
| Preceded by | Talha ibn Tahir | 
| Succeeded by | Tahir ibn Abdallah | 
| Governor of Egypt | |
| In office 826–827 | |
| Monarch | Al-Mamun | 
| Preceded by | Ubaydallah ibn al-Sari | 
| Succeeded by | Isa ibn Yazid al-Juludi | 
| Governor of Syria | |
| In office 820–822 | |
| Monarch | Al-Mamun | 
| Preceded by | Muhammad ibn Salih ibn Bayhas (810–820) | 
| Succeeded by | Abu Ishaq Muhammad ibn Harun al-Rashid | 
| Personal details | |
| Born | 798 Iran | 
| Died | 845 (aged 46–47) Nishapur | 
| Children | Tahir ibn Abdallah Muhammad ibn Abdallah Ubaydallah ibn Abdallah Sulayman ibn Abdallah | 
| Parent | Tahir ibn Husayn | 
Abdallah ibn Tahir (Persian: عبدالله طاهر, Arabic: عبد الله بن طاهر الخراساني) (ca. 798–844/5) was a military leader and the Tahirid governor of Khurasan from 828 until his death. He is perhaps the most famous of the Tahirids. His career spanned twenty-five years under three caliphs, al-Ma'mun, al-Mu'tasim, and al-Wathiq. Militarily, he is known for defeating the powerful rebels Nasr ibn Shabath in the Jazira (Upper Mesopotamia) and Ubaydallah ibn al-Sari in Egypt.