Al-Sadr (Arabic: الصدر) is a Lebanese-Iraqi-Iranian clerical Shia family originating from Jabal Amel in Lebanon.
They are a branch of Musawi family tracing to Musa Ibn Jaafar the seventh Shia Imam.
Sadr is a branch of Charafeddine (Arabic: شرف الدين) family from Jabal Amel in Lebanon.
The Charafeddine family itself is a branch of the Noureddine family, which traces its lineage to Moussa al-Kazim (the seventh Shi'a Imam) and through him to the first Imam, Ali ibn Abi Talib and Fatima Zahra, the daughter of Muhammad (d.632).
Ancestor of the Sadr family, Sayyed Saleh Moussawi Ameli, was a descendant of Musa Al Kadhim, the seventh Shi'a Imam, through 27 generations: Source:[1]