The Joined Underwing or Stretch's Underwing (Catocala junctura) is an Erebidae species. It is found throughout temperate North America. The species ranges from New York and Pennsylvania west to Montana, Colorado, Oklahoma, Arizona and into Texas, and north to southern Illinois, extreme southern Alberta and Saskatchewan; it has also been recorded west of the Rocky Mountains from California and south-eastern British Columbia. It is typically found near water, where the foodplants of its caterpillar larvae grow plentifully.