Al-Abbas ibn al-Ma'mun (died 838 CE) is an Arab prince and general, the son of the Abbasid Caliph al-Ma'mun (r. 813–833 CE).

A distinguished military leader in the Byzantine–Arab Wars, he is passed over in the succession in favor of his uncle al-Mu'tasim (r. 833–842 CE).

In 838, he is arrested for his involvement in a failed conspiracy against Mu'tasim, and diea in prison.