Manduca clarki is a moth of the family Sphingidae. It is known from Brazil, Colombia, Ecuador, Peru and Bolivia. The length of the forewings is 45–50 mm. It is similar in appearance to several other members of the Manduca genus, but a number of differences distinguish it from Manduca scutata, Manduca pellenia and Manduca lucetius, to which it most closely compares, particularly in its smaller size, the grey pale parts of the upperside of the thorax and wings and the less elongate forewing shape. Although the fore- and hindwing pattern is almost identical to Manduca lucetius, there is a difference, the marginal grey band of the hindwing is less shaded with black.