Zīj-i Sulṭānī (Persian: زیجِ سلطانی) is a Zij astronomical table and star catalogue that was published by Ulugh Beg in 1438–1439. It was the joint product of the work of a group of Muslim astronomers working under the patronage of Ulugh Beg at Samarkand's Ulugh Beg Observatory. These astronomers included Jamshīd al-Kāshī and Ali Qushji, among others. The Zij-i-Sultani was not surpassed in accuracy until the work of Taqi al-Din and Tycho Brahe in the 16th century.