We report 82 species of butterflies (Lepidoptera: Rhopalocera) from Sapelo Island, GA, a 4414-ha barrier island located ∼10 km from the mainland, based on monthly records from 2012 through 2019. This fauna consists of 7 species of papilionids, 9 species of pierids, 13 species of lycaenids, 1 species of riodinid, 21 species of nymphalids, and 31 species of hesperiids, including 1 species of giant skipper (Megathyminae). Based on collection records and available larval foodplants, it appears that most of these butterflies have likely established populations on the island, but a few species are migratory or transitory and may be rare or absent in some years. Some butterfly species that occur on the adjacent mainland have not been recorded on Sapelo Island, including species with larval foodplants associated with established freshwater or brackish habitats.