Abū al-Sāj, Dīwdād b. Dīwdast (d. Rabīʿ II 266/December 879), was one of the famous emirs, commanders and officials of the ʿAbbāsid administration, and forebear of the Sājid dynasty. Al-Ṭabarī (9/315) recorded his kunya as Abū Jaʿfar.

Abū al-Sāj's name was erroneously recorded in some sources as Dāwūd b. Dūst (Ibn Khallikān, 6/415). According to Henning (pp. 253–254), Abū al-Sāj's father's name was probably Dīwdasht rather than Dīwdast (Ibn Ḥawqal, 2/506: Dāwdasht), and Dīwdasht is another form of Dīwdād, meaning ‘someone whose creator is the divinity’ (cf. Dihkhudā, 8/11447 under dī…