Chai (Chinese: 柴; pinyin: Chái; Wade–Giles: Ch'ai, also spelled as Tsai, Tchai) is a Chinese surname. The same surname is Sài in Vietnamese, and Si (시, sometimes spelled as Shi, See, Sie, Sea) in Korean.
Chai is listed 325th in the Song dynasty classic text Hundred Family Surnames.[1] As of 2008, it is the 127th most common surname in China, shared by 1.35 million people.[2]