The Lineella Underwing, Little Lined Underwing or Steely Underwing (Catocala lineella) is a moth of the Erebidae family. It is found from Ontario and Quebec south to Florida west to Texas and north to Ohio. It was considered to be a subspecies or even a synonym of Catocala amica for a long time. The wingspan is 35–40 mm. Adults are on wing from July to August. The larvae feed on the leaves of Quercus species.