Yahya al-Mu `tasim (Arabic: أبو زكرياء المعتصم يحي بن الناصر; Abū Zakarīyā' Al-Mu`taṣim Yaḥyā ibn An-Nāṣir; died 1236) was an Almohad rival caliph who reigned in Marrakech from 1227.
At the death of Abdallah al-Adil, he was supported by the sheikhs of Marrakech, but two years later he was turned down by other pretender, Idris I. At the latter's death in 1232, Yahya renewed his pretenses, but Abd al-Wahid II was preferred to him. He was anyway able to keep Marrakech until his death in 1236, after which the Almohad territories were again united under Abd-al Wahid.
| Preceded by Abdallah al-Adil |
Almohad dynasty 1227–1229 |
Succeeded by Abd al-Wahid II |