Buddhist monk and founder of the Hwaŏm (Chinese: Hua-yen) sect of Korean Buddhism. He devoted himself to the propagation of the teaching of the Avataṃsaka-sūtra (Garland Sutra), which provided ideological support for the political system of the state of Unified Silla (668–935).

Ŭisang became a monk about 650, and at 37 he went with his friend the monk Wŏnhyo to China, where he studied the Garland Sutra under the direction of Chih-yen, the 2nd patriarch of the Chinese Hua-yen (Garland) sect. While in China he wrote his major work, An Explanatory Diagram on the Garland World System, which elicited high acclaim from his master and is still read widely in the Buddhist circles of East Asia. On returning home in 671, he built, sponsored by King Munmu, the Pusŏk Temple as the centre of the Hwaŏm sect.