Al-Hasan ibn Sahl (Arabic: الحسن بن سهل; died 850/51) was an Abbasid official and governor of Iraq for Caliph al-Ma'mun (reigned 813–833) during the Fourth Fitna.
[1] During the civil war of the Fourth Fitna against Ma'mun's half-brother al-Amin (r. 808–813), he was entrusted with the supervision of the land tax (kharaj) office.
[1] In early 815, the Zaydi Alid revolt of Ibn Tabataba and Abu'l-Saraya broke out at Kufa and spread quickly through southern Iraq.
Hasan proved unable to confront it, and the rebels at one point threatened Baghdad itself before the intervention of the capable general Harthama ibn A'yan led to the suppression of the revolt.
[1] In 825, however, he married his daughter, Buran (807–884), to Ma'mun, and gave her as dowry the palace of Qasr al-Hasani, south of Baghdad, which thereafter became one of the caliphal residences.