The Di (Chinese: 氐; pinyin: Dī; Wade–Giles: Ti1;[1] < Eastern Han Chinese *tei[2] < Old Chinese (B-S): *tˤij) were an ancient ethnic group that lived in western China, and are best known as one of the non-Han Chinese peoples known as the Five Barbarians that seized power in northern China during the Sixteen Kingdoms period. This ethnic group should not be confused with the earlier Dí (狄), which refers to unrelated nomadic peoples in northern China during the earlier Zhou dynasty. The Di are thought to have been of proto-Tibetan origin,[3][4][5] though there is a widespread belief among Chinese scholars that the Di spoke a Turkic language.[6] The Ba-Di (巴氐) were a branch of the Di that intermixed with another ethnic group known as the Cong people (賨).
Only a few special Di names and place names have been preserved in old Chinese books.[7][8][9]