Sadr al-Din Musa (1305–1391) (Persian: صدرالدین موسی) was the son and successor of Safi-ad-din Ardabili.

During this time, the activities of the Safaviyya were viewed with favour by Timur, who provided an endowment for the shrine of Safi-ad-din Ardabili in Ardabil, and allowed Sadr al-Din to collect taxes.

Timur also offered Sadr al-Din to request any favour from himself, and Sheikh Sadr al-Din asked for the release of Turkish prisoners captured by Timur from Diyarbakır.

Timur accepted this request, and the freed prisoners became Sadr al-Din's loyal disciples.

The descendants of these freed prisoners, emigrating by the thousands into Gilan province, would later aid his family to found a dynasty.