The Grey Amphipyra or Smooth Amphipyra (Amphipyra glabella) is a moth in the Noctuidae family. It is found from New York and Quebec west to southern British Columbia, south to Georgia and Colorado. The wingspan is 33–40 mm. Adults are on wing from August to September depending on the location. There is one generation per year. The larvae feed on the leaves of Populus balsamifera and Pseudotsuga menziesii in the western parts of its range.