Wey (, commonly spelled Wey to distinguish it from the other Wei state) was an  ancient Chinese state that was founded in the Zhou Dynasty and rose to prominence during the Spring and Autumn Period. Its rulers were of the surname Ji (姬), the same as that of the rulers of Zhou. Its original location was on the North China Plain just east of the Shanxi plateau and north and west of the Yellow River. Jin was to the west and Cao to the east.