Wei

Wei or WEI may refer to:

States

Wey (state) (衛, 1040–209 BC), Wèi in pinyin, but spelled Wey to distinguish from the bigger Wèi of the Warring States
Wei (state) (魏, 403–225 BC), one of the seven major states of the Warring States period
Cao Wei (曹魏, 220–266), ruled North China during the Three Kingdoms period
Ran Wei (冉魏, 350–352), short-lived Sixteen Kingdoms period state
Northern Wei (北魏, 386–535), ruled North China during the Southern and Northern Dynasties, later split into:

One of three Chinese constellations:
- Wěi (尾), meaning Tail
- Wēi (危), meaning Rooftop
- Wèi (胃), meaning Stomach
Wèi (魏), the Chinese name for the star Delta Herculis
Wei, a name sometimes used for Epsilon Scorpii, after the Tail constellation

WEi, a South Korean boy group
Wei (rank), a company-grade officer in Chinese armed forces
Wei (value token), a subunit of the Ether value token on the Ethereum blockchain
Wau Ecology Institute, Wau, Papua New Guinea
Web Environment Integrity, a Web API proposed by Google
Windows Experience Index (WEI) score, a measure of the user-perceived performance of a computer running Microsoft Windows
Weipa Airport (IATA code: WEI), Weipa, Queensland, Australia
Wei Empire, a fictional state and planetary romance series of Yulia Latynina