Musa ibn Yahya (Arabic: موسى بن يحيى, romanized: Mūsā ibn Yaḥyā) was a member of the powerful Barmakid family in the service of the Abbasid Caliphate.

According to a report relayed by al-Tabari, at the same time Musa had to go into hiding from his debtors, so the Caliph became suspicious that he was about to secretly go to Khurasan; when Musa appeared before the Caliph, he had him arrested, and released only after his father vouchsafed for him.

[4] When the Barmakids were deposed and arrested by Caliph Harun al-Rashid in 803, Musa too was imprisoned with his father and brothers until the accession of al-Amin, who released them and showed them again some favour.

[1] During the Fourth Fitna, Musa sided with al-Amin, fighting in the ranks of the loyalist army against al-Ma'mun, but he later entered the latter's service.

[1][2] A grandson of Musa, Ahmad ibn Ja'far, surnamed Jahza, was one of the closest companions of the 10th century Caliph al-Muqtadir (r. 908–932).