Degelia cyanoloma (Schaer.) H. H. Blom & L. Lindblom is resurrected from synonymy and elevated from varietal rank to species. The taxon was earlier referred to D. plumbea (Lightf.) P. M. Jørg. & P. James, however, several discontinuous character states distinguish the two species. Degelia cyanoloma is characterized morphologically by having a large thallus that is pale greyish when dry, lobes that are composed of consecutive trough-shaped segments with an upper surface without squamules, no isidia or soredia, and apothecia discs that are dark reddish brown to blackish. Degelia cyanoloma has a euoceanic distribution and is known from western Europe (Norway, France, Great Britain, Ireland, Portugal, Spain). Based on results from studies of morphology, we hypothesize that D. atlantica (Degel.) P. M. Jørg. & P. James is the closest relative of D. cyanoloma among the European species of the genus whereas D. plumbea is closely related to D. ligulata P. M. Jørg. & P. James.