Ja'far ibn Yahya

Jaʽfar ibn Yahya جعفر بن يحيى
Detail of a miniature illustrating an anecdote in which the power and influence of Jaʻfar ibn Yahya (crowned figure) is pointed out. Folio from a manuscript of Nigaristan, Iran, probably Shiraz, dated 1573-74
Born	c. 767 Khorasan, Abbasid Caliphate
Died	c. 803 Abbasid Caliphate
Cause of death	Execution on the orders of Caliph Harun al-Rashid
Other names	Aba-Fadl
Occupation	Abbasid vizier
Years active	c. 798 – 803
Era	Abbasid
Parents	Yahya ibn Khalid (father) Umm al-Fadl (mother)

Jaʽfar ibn Yahya Barmaki or Jafar al-Barmaki (Persian: جعفر بن یحیی برمکی, Arabic: جعفر بن يحيى, Jaʽfar bin yaḥyā) (767–803), also called Aba-Fadl, was a Persian vizier of the Abbasid caliph Harun al-Rashid, succeeding his father (Yahya ibn Khalid) in that position. He was a member of the influential Barmakid family, formerly Buddhist leaders of the Nava Vihara monastery. He was executed in 803 at the orders of Harun al-Rashid.

He had a reputation as a patron of the sciences, and did much to introduce Indian science into Baghdad.^[1] He was credited with convincing the caliph to open a paper mill in Baghdad, the secret of papermaking having been obtained from Tang Chinese prisoners at the Battle of Talas (in present-day Kyrgyzstan) in 751.^{[citation needed]}