Jāmiʿ al-bayān ʿan taʾwīl āy al-Qurʾān, popularly Tafsīr al-Ṭabarī, is a Sunni tafsir by the Persian scholar Muhammad ibn Jarir al-Tabari (838–923). It immediately won high regard and has retained its importance for scholars to the present day. It is the earliest major running commentary of the Quran to have survived in its original form. Like his history, al-Tabari's tafsir is notable for its comprehensiveness and citation of multiple, often conflicting sources. The book was translated into Persian by a group of scholars from Transoxania on commission of the Samanid king, Mansur I (961–976).

Tafsir refers to exegesis, usually of the Quran. An author of a tafsir is a mufassir. A Quranic tafsir attempts to provide elucidation, explanation, interpretation, context or commentary for clear understanding and conviction of God's will in Islam.