Jimmy Yu (born 1968), also known as Guo Gu (果谷 Guǒ Gǔ), is a Chan teacher and a scholar of Buddhism.

After his youthful days in hardcore straight edge, he returned to Buddhism and became a monk under Chan Master Sheng Yen.

His research interests include the history of the body, Buddhist monasticism, Chan/Zen Buddhism, and popular religions within the broader context of fifteenth- to seventeenth-centuries China.

Guo Gu was Sheng Yen's translator, attendant, and assistant in leading intense Chan retreats.

This former explores the religious aspects of self-inflicted violence, such as texts written in blood and the occasional practice of cannibalism during times of famine in late Ming and early Qing China, and the latter is the first socio-intellectual history of the Dharma Drum Lineage of Chan (Zen) by Master Sheng Yen, challenging the received academic and popular image of Chan Buddhism as a meditation school that bypasses scriptural learning.