Abu Nu`aym al-Isfahani ( أبـو نـعـيـم الأصـفـهـانـي; full name Ahmad ibn `Abd Allāh ibn Ahmad ibn Ishāq ibn Mūsā ibn Mahrān al-Mihrānī al-Asbahānī (or al-Asfahānī) al-Ahwal al-Ash`arī al-Shāfi`ī, d. 1038 / AH 430) was a medieval Muslim scholar. Born in Buwayhid era Isfahan, he travelled widely, visiting Nishapur, Basra, Kufa, Baghdad, Mecca and Andalusia. He is the presumed author of Hilyat al-awliya' , one of the most important sources for the early development of Sufism, and a transmitter of Shafi'i hadith.
The Hilyat al-awliya' is a substantial work in ten volumes, comprising a total of 650 biographies, amounting to about 4,000 pages in the printed edition. The work includes many biographies of early Islam, including the six Shi'a Imams. Most biographies of individuals that are directly involved with the development of Sufi mysticism are found in the tenth volume.