The Great Emperor of the North Star, also called the Ziwei Emperor (紫微) and the Beiji Emperor, is one of the highest sky deities and one of the Four Sovereigns (四御; sì yù) of Taoism.

The Ziwei Emperor resides in the middle of Heaven and assists the Jade Emperor in administrative duties of Heaven and Earth; Sun and Moon; four seasons and weather. He commands all deities of constellations, mountains, and rivers. He is the highest deity in charge of all the natural phenomena in the universe. In Chinese culture and Chinese theology, the Ziwei Emperor is also the symbol of the emperor in the human world.