A new species of crayfish, Cambarus (Jugicambarus) magerae, is described from southwestern Virginia within the Valley and Ridge physiographic province of the North American Appalachian Mountains. The species is one of the smallest and most geographically restricted in the subgenus and possibly the genus. Morphologically, it is similar to Cambarus (J.) parvoculus Hobbs & Shoup, 1947 and Cambarus (J.) jezerinaci Thoma, 2000. It can be distinguished from both by its proportionally wider areola. Its distribution appears to be restricted to a single gorge in the South Fork Powell River upstream of Cracker Neck, a village east-southeast of Big Stone Gap located at the base of Powell Mountain.