Atâ-Malek Juvayni (1226–1283) (Persian: عطاملک جوینی), in full, Ala al-Din Ata-ullah (Persian: علاءالدین عطاءالله), was a Persian historian who wrote an account of the Mongol Empire entitled Tarīkh-i Jahān-gushā (History of the World Conqueror).
He was born in Juvayn, a city in Khorasan in eastern Persia. Both his grandfather and his father, Baha al-Din, had held the post of sahib-divan or Minister of Finance for Muhammad Jalal al-Din and Ögedei Khan respectively. Baha al-Din also acted as deputy c. 1246 for his immediate superior, the emir Arghun, in which role he oversaw a large area including Georgia and Armenia.
Juvayni too became an important official of the empire. He visited the Mongol capital of Karakorum twice, beginning his history of the Mongols conquests on one such visit (c. 1252-53). He was with Ilkhan Hulagu in 1256 at the taking of Alamut and was responsible for saving part of its celebrated library. He had also accompanied Hulagu during the sack of Baghdad in 1258, and the next year was appointed governor of Baghdad, Lower Mesopotamia, and Khuzistan. Around 1282, Juvayni attended a Mongol quriltai, or assembly, held in the Ala-Taq pastures northeast of Lake Van. He died the following year in Mughan or Arran in Azerbaijan.
Juvayni's brother was the powerful Shams al-Din Mohammad Sahib-Divan, who had served as Minister of Finance under Hulagu and Abaqa Khan. A skillful leader in his own right, Shams al-Din also had influential in-laws: his wife Khoshak was the daughter of Awak Zak'arean-Mkhargrdzeli, Lord High Constable of Georgia, and Gvantsa, a noblewoman who went on to become queen of Georgia.
Juvayni's own position at court and his family connections made him privy to information unavailable to other historians. For unknown reasons Juvayni's history terminates in 1260, more than twenty years before his death.
The standard edition of Juvayni's history is published under the title Tarīkh-i Jahān-gushā, ed. Mirza Muhammad Qazwini, 3 vol, Gibb Memorial Series 16 (Leiden and London, 1912–37). An English translation by John Andrew Boyle The History of the World-Conqueror was republished in 1997.