The Di (; Old Chinese: *tˁij) was an ancient ethnic group that lived in western China, and are best known as one of the non-Han Chinese peoples that overran northern China during the Jin Dynasty (265–420) and the Sixteen Kingdoms period. This ethnic group should not be confused with the 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, though there is a widespread belief among Chinese scholars that the Di have spoken an Altaic (specifically Turkic) language.