Catocala is a generally Holarctic genus of owlet moths (family Noctuidae or superfamily Noctuoidea – see below) commonly known as underwing moths or simply underwings. These terms are sometimes used for a few related moths, but usually – especially when used in plural, not as part of a species name – it is used to refer to Catocala only. They are traditionally placed in the subfamily Catocalinae, and therein in subtribe Catocalina of the large tribe Catocalini. Of these taxa, they form the type genus.
Of the more than 250 known species, slightly less than half are found in North America – mostly in the United States – while the rest occur in Eurasia. Of these, about one-fifth (almost 30 species) is native to Europe. A few range into the northern Neotropics and Indomalaya.