Phelsuma grandis Gray, 1870, is a diurnal arboreal species of day gecko (Phelsuma spp.). These geckos are part of the Phelsuma group, which consists of in excess of 70 species and subspecies. They are commonly referred to as the Madagascar giant day gecko, due to their large size. They are found in areas of tropical and subtropical forest in northern Madagascar. P. grandis feeds on various invertebrates, very small vertebrates, and nectars.