Planuncus is a genus of cockroaches native to Old World (especially Europe) described by Bohn in 2013 and belonging to the family Ectobiidae, subfamily Ectobiinae. The genus was only recently erected in an ongoing effort to create better groupings of species in the Ectobiinae and is composed of species previously classified as Ectobius and that share a number of characters to set these off from other species in these genera. The defining characters are mainly in the male genitalia and subgenital plate, so externally the species of the genus are not clearly separable by a common denominator from the remaining species still in the genera Ectobius or Phyllodromica.