Lophostethus dumolinii is a moth of the family Sphingidae. It is known from most habitats, except desert and high mountains throughout the Ethiopian Region, excluding Madagascar and the Cape in South Africa. The length of the forewings is 55–70 mm for males and 70–75 mm for females and the wingspan is 130–171 mm. This species has a characteristic colour and pattern of the upperside of the thorax and forewing. The forewing upperside ground colour is pale brown with paler undulating antemedian and postmedian lines.