The Afrotropical genus Oreoeudesis Franz was previously known to occur in Tanzania, Kenya and Cameroon. A new species, Oreoeudesis ruandensis sp. nov. is described on the basis of a material coming from Rwanda. Differences in cephalic, pronotal, mesonotal and genital structures justify placing the new species in a separate subgenus, Suboreon subgen. nov. Morphological structures of O. ruandensis, especially the large composite eyes and fully developed wings, seem to be plesiomorphic as compared to derived character states in the previously known, microphthalmous or anophthalmous and wingless species.