Abū Ḥātim al-Muẓaffar al-Isfazārī was an Islamic mathematician, astronomer and engineer from Khurasan. According to the historian and geographer Ibn al-Athir and the polymath Qutb al-Din al-Shirazi, he worked in the Seljuq observatory of Isfahan. The Persian writer Nezami Aruzi met him in Balkh in in 1112 or 1113.