Nasir al-Din Abu al-Khair 'Abdullah ibn 'Umar al-Baydawi (Arabic: ناصر الدين أبو الخير عبد الله بن عمر بن محمد البيضاوي), also known as Baidawi, was a Muslim scholar, born in Fars, where his father was chief judge, in the time of the Atabek ruler Abu Bakr ibn Sa'd (1226–60). He himself became judge in Shiraz, and died in Tabriz about 1286. Many commentaries have been written on Baidawi's work. He was also the author of several theological treatises.
His major work is the commentary on the Qur'an entitled The Secrets of Revelation and The Secrets of Interpretation (Asrar ut-tanzil wa Asrar ut-ta'wil)'. This work is largely a condensed and amended edition of al-Zamakhshari's (al-Kashshaf). That work, which displays great learning, suffers from Mu'tazilite views which al-Baydawi has tried to amend, sometimes by refuting them and sometimes by omitting them. It has been edited by Heinrich Leberecht Fleischer (2 vols., Leipzig, 1846-1848; indices ed. W. Fell, Leipzig, 1878). There are many editions published in the East. A selection with numerous notes was edited by D. S. Margoliouth as Chrestomathia Beidawiana (London, 1894).