The Rosner's Hairstreak (Callophrys rosneri) is a butterfly of the Lycaenidae family. It is found in British Columbia. and Washington state. Subspecies plicataria is known as Barry's Hairstreak. The wingspan is 21–27 mm. The larvae of ssp. rosneri feed on Western Red Cedar (Thuja plicata), while the larvae of ssp. plicataria feed on Rocky Mountain Juniper (Juniperus scopulorum).