The greater wax moth, Galleria mellonella Linnaeus, is well known as a pest of honey bees and for the biodegradation of wax and polyethylene by their larvae. The genus Galleria has long been considered monotypic and found worldwide. A taxonomic study of the genus Galleria is presented based on morphological and molecular characters (COI, CAD, wg). A new species (Galleria similis Roh & Song, sp. nov.) is recognized on the Korean peninsula. The new species is superficially similar to G. mellonella but they can be separated by the structures of hindwing venation and male genitalia. Habitus photographs and illustrations of diagnostic characters are provided.