Korean folklorist. After having studied journalism at Hongik University, Sim U-seong dedicated himself from 1959 to the revival of kkoktu-gakski norum (ggokdu gaksi noreum), the puppetry of the namsadang itinerant troupes (see Namsadang). He is director of the Gongju Folk Drama Museum.

As a specialist in traditional arts, in 1965 he facilitated the nomination of the Namsadang troupe for status as an intangible cultural property. In 1966, the designation was given. He founded the Seonang-Dang Theatre and performed the Adventure of Hong Donji and Ssangdu-a (Two-headed Child) at Space Theatre in 1982. He sought to integrate Korean puppet traditions with shamanism.

He became interested in mime (The Portal The Gate and The Namdo Fields Song, the latter a workers’ song from the southern province) and performed these as his own solo pieces.

In 1996, Sim U-seong organized the first solo theatre festival in Gongju and followed it by another in 2005. He is the author of Namsadang Nori and Traditional Korean Theatre (1971). In 2005, he was elected vice president of the special committee of the National Cultural Asset Administration concerned with cultural heritage.

(See Korea.)