GU, Gu or gu may refer to:
* Gu (clan), Gu (family), several rare surnames of the Han Chinese people
* Gu (food), a sports nutrition product
* Gu (god), the Dahomey god of war
* Gu (poison), Chinese poison sorcery
* Gu (surname), a last name of the Chinese and Korean people
* Gu County, in Shanxi, China
* Gu, "district", an administrative division of South Korea
* GU Comics, an online comic.
* GU4 or GUD (ð’„ž), the Sumerian for "bull"
* g.u. - a Japanese fashion retail chain
o Gu-anna, the "Heavenly Bull", the Sumerian name for Taurus
* Gu (violin), a type of violin used in the Shetland Islands, also gue or gju.
* Gu (drinking vessel), a Chinese wine beaker from the Shang and Zhou dynasties, also ku.