A new species of medium-sized Sphenomorphus is described from the biogeographically enigmatic island of Palawan in the western Philippines. This species represents only the third skink in the genus Sphenomorphus found on Palawan Island. The new species is compared with other Sphenomorphus found on Palawan and with phenotypically similar species in the genus from throughout its range. To aid in future identification of Sphenomorphus specimens from Palawan, we provide a key to the species from this island.