Al-Abbas ibn al-Ma'mun

Al-Abbas ibn al-Ma'mun العباس إبن المأمون
Died	838
Burial	Manbij
Names Al-Abbas ibn Abdallah al-Ma'mun ibn Harun al-Rashid ibn Muhammad al-Mahdi ibn Abdallah al-Mansur
Dynasty	Abbasid
Father	al-Ma'mun
Mother	Sundus
Religion	Sunni Islam
Military career
Allegiance	Abbasid Caliphate
Service/branch	Abbasid army
Years of service	c. 828–838
Battles/wars	Arab–Byzantine wars
Relations	al-Amin (uncle) al-Mu'tasim (uncle) al-Qasim (uncle)

Al-Abbas ibn al-Ma'mun (Arabic: العباس بن المأمون) (died 838 CE) was an Abbasid prince and general, the son of the Abbasid caliph al-Ma'mun (r. 813–833). A distinguished military leader in the Arab–Byzantine wars, he was passed over in the succession in favour of his uncle al-Mu'tasim (r. 833–842). In 838, he was arrested for his involvement in a failed conspiracy against al-Mu'tasim, and died in prison.