The Acadian Hairstreak (Satyrium acadica) is a butterfly of the Lycaenidae family. It is found from British Columbia east to Nova Scotia and south to Idaho, Colorado, the northern Midwest, Maryland, and New Jersey. The wingspan is 29–38 mm. There is one tail on each hindwing. The upperside is brown-grey, while the underside of the hindwings is grey. Adults are on wing from June to August in one generation per year. They feed on flower nectar of various flowers. The larvae feed on the leaves of Salix species, including Salix nigra and Salix sericea. The species overwinters as an egg.