Gephyromantis blanci, commonly known as the white Madagascar frog, is a species of frog in the family Mantellidae. It is endemic to Madagascar and is found in the southeast of the island. Its natural habitat rainforest leaf litter; it tolerates some habitat degradation. It is not dependent on water and is presumed to reproduce through direct development. It is threatened by habitat loss. It occurs in Ranomafana, Midongy du sud, and Andringitra National Parks.