Abū Saʿīd ʿAbd-al-Ḥayy ibn Żaḥḥāk b. Maḥmūd Gardīzī (Persian: ابوسعید عبدالحی بن ضحاک بن محمود گردیزی), better known as Gardizi (گردیزی), was an 11th-century Persian^[1] historian and official, who is notable for having written the Zayn al-akhbar, one of the earliest history books written in New Persian.^[2]

Little is known of Gardizi personally. He was probably from Gardiz in the region of Zamindawar, as his nisba implies.^[3] His father's name was Zahhak, a name that was seemingly popular in the region.^[1] Gardizi started his career as an official of the Ghaznavid monarch Mahmud of Ghazni (r. 998–1030), and was an eyewitness to many of the events that occurred under the latter.^[2] In his Zayn al-akbar, Gardizi took a dispassionate view of history which was fairly remarkable for its time.^[1] It consisted of a history of the pre-Islamic kings of Iran, Muhammad and the Caliphs until the year 1032. Included is a history of the Arab conquest of Khorasan, which it is believed Gardizi was using al-Sallami as a source. His history concerning the Turks was written using Ibn Khordadbeh, Jayhani and Ibn al-Muqaffa' as sources.^[4] He may have been a student of al-Biruni, since the Zayn al-akbar contains information concerning Indian festivals.^[4]