Callomyia triangulata sp. nov. is described from South China (Yunnan Province) based on two females. The species is compared with the only other species of Callomyia Meigen, 1804 known from the Oriental Region, C. coei Kessel, 1966 from Nepal, from which it differs mainly by the thoracic and abdominal colouration. All relevant characters are illustrated and photographed. A probable Palaearctic origin of these two species is discussed.