Daimio tethys is a species of butterfly of the family Hesperiidae. It is found in eastern Asia, including the Amur region, southern Ussuri, Japan, Taiwan and Korea. The wingspan is about 40 mm. The larvae feed on various plants, including Quercus mongolica, Dioscorea nipponica, Dioscorea butatas, Dioscorea japonica and Dioscorea japonica var. pseudojaponica.