Abū Jaʿfar Muḥammad ibn Jarīr ibn Yazīd al-Ṭabarī (Arabic: أَبُو جَعْفَر مُحَمَّد بْن جَرِير بْن يَزِيد ٱلطَّبَرِيّ; 839–923 CE / 224–310 AH), commonly known as al-Ṭabarī (Arabic: ٱلطَّبَرِيّ), was a Sunni Muslim scholar, polymath, historian, exegete, jurist, and theologian from Amol, Tabaristan, present-day Iran. Among the most prominent figures of the Islamic Golden Age, al-Tabari is widely known for his historical works and expertise in Quranic exegesis, and has been described as "an impressively prolific polymath". He authored works on a diverse range of subjects, including world history, poetry, lexicography, grammar, ethics, mathematics, and medicine. Among his most famous and influential works are his Quranic commentary, Tafsir al-Tabari, and historical chronicle, Tarikh al-Tabari.

Al-Tabari followed the Shafi'i school for nearly a decade before he developed his own interpretation of Islamic jurisprudence. His understanding of it was both sophisticated and remarkably fluid, and, as such, he continued to develop his ideas and thoughts on juristic matters right until the end of his life.

Al-Tabari's school of jurisprudence "flourished among Sunni ulama for two centuries after his death", before it eventually became extinct. It was commonly designated as the Jariri school.

Tabari was born in Amol, Tabaristan (some 20 km south of the Caspian Sea) in the winter of 838–39. He has been described as either of Persian or Arab origin. He memorized the Qur'an at seven, was a qualified prayer leader at eight, and began to study the prophetic traditions at nine. He left home to study in 236 AH (850/1 AD), when he was twelve. He retained close ties to his hometown. He returned at least twice, the second time in 290 AH (903 AD), when his outspokenness caused some uneasiness and led to his quick departure.

He first went to Ray (Rhages), where he remained for some five years. A major teacher in Rayy was Abu Abdullah Muhammad ibn Humayd al-Razi, who had earlier taught in Baghdad, but was now in his seventies While in Ray, he also studied Muslim jurisprudence according to the Hanafi school. Among other material, ibn Humayd taught Jarir Tabari the historical works of ibn Ishaq, especially al-Sirah, the life of Muhammad. Tabari was thus introduced in youth to pre-Islamic and early Islamic history. Tabari quotes ibn Humayd frequently, but little is known about Tabari's other teachers in Rayy.

Tabari then travelled to study in Baghdad under Ahmad ibn Hanbal, who, however, had recently died (in late 855 or early 856). Tabari possibly made a pilgrimage prior to his first arrival in Baghdad. He left Baghdad probably in 242 AH (856/7 AD) to travel through the southern cities of Basra, Kufah and Wasit. There, he met a number of eminent and venerable scholars. In addition to his previous study of Hanafi law, Tabari also studied the Shafi'i, Maliki and Zahiri rites. Tabari's study of the latter school was with the founder, Dawud al-Zahiri, and Tabari hand-copied and transmitted many of his teacher's works. Tabari was then well-versed in four of the five remaining Sunni legal schools, before founding his own independent, yet eventually extinct, school. His debates with his former teachers and classmates were known, and served as a demonstration of said independence. Notably missing from this list is the Hanbali school, the fourth largest legal school within Sunni Islam in the present era. Tabari's view of Ibn Hanbal, the school's founder, became decidedly negative later in life. Tabari did not give Ibn Hanbal's dissenting opinion any weight at all when considering the various views of jurists, stating that Ibn Hanbal had not even been a jurist at all but merely a recorder of Hadith.

On his return to Baghdad, he took a tutoring position from the vizier, Ubaydallah ibn Yahya ibn Khaqan. This would have been before A.H. 244 (858), since the vizier was out of office and in exile from 244 to 248 (858–9 to 862). There is an anecdote telling that Tabari had agreed to tutor for ten dinars a month, but his teaching was so effective and the boy's writing so impressive that the teacher was offered a tray of dinars and dirhams. The ever-ethical Tabari declined the offer, saying he had undertaken to do his work at the specified amount, and could not honorably take more. That is one of a number of narratives about him declining gifts or giving gifts of equal or greater amount in return.

In his late twenties, he travelled to Syria, Palestine, India and Egypt. In Beirut, he made the highly significant connection of al-Abbas ibn al-Walid ibn Mazyad al-'Udhri al-Bayruti (c. 169–270/785–86 to 883–84). Al-Abbas instructed Tabari in the Syrian school's variant readings of the Qur'an and transmitted through his father al-Walid the legal views of al-Awza'i, Beirut's prominent jurist from a century earlier.^{[citation needed]}