Abd al-Ali al-Birjandi

ʿAbd al-ʿAlī al-Bīrjandī (died 1528) was a Persian astronomer, mathematician and physicist who worked in Birjand, in Khurasan; his birth date is unrecorded. He produced a string of technical commentaries, chief among them the Sharḥ al-Tadhkirah on Nasir al-Din al-Tusi's astronomical treatise, completed in 1507–1508.

In the commentary he tested the claim that a falling stone disproves the Earth's rotation, arguing that a stone dropping perpendicular to the horizon could remain compatible with a moving Earth.

Birjandi also wrote on astronomical instruments and on constructing almanacs. He died in 1528 and was buried at Bojd near Birjand.