A new species of Zographetus Watson, 1893 (Lepidoptera, Hesperiidae, Hesperiinae) is described from the Western Ghats of Peninsular India. Zographetus mathewi Sadasivan and Kochunarayanan, sp. nov., fits in the Z. satwa species-group based on the forewing venation, with vein Cu 2 arising much closer to the wing base than vein Cu 1 , and the basal portion of vein Cu 2 and the cubitus up to the origin of Cu 1 swollen. Field images of adults, illustrations of genitalia and information on the early stages of this species are also provided. The larval host plant was identified as Aganope thyrsiflora (Fabaceae). A key to the species of the Oriental genus Zographetus is also provided.