Wei (/weɪ/; Chinese: 衞; pinyin: Wèi), commonly spelled Wey to distinguish from the contemporary larger Wei (魏) state, was an ancient Chinese state that was founded in the early Western Zhou dynasty and rose to prominence during the Spring and Autumn period.

It was located in modern northeastern Henan Province, east of Jin (and later Wei 魏), and west of Cao.

The history of Wey dates back to the beginning of the Zhou dynasty and the Rebellion of the Three Guards.

It was only with the aid of Duke Huan of Qi that the state was eventually restored, with its capital moved to Chuqiu.

In 239 BCE the state of Qin occupied Puyang, and Wey migrated to Yewang (野王) in order to preserve its existence.