Arctomia is a genus of lichen-forming fungi in the family Arctomiaceae. The genus was originally circumscribed by Theodor Magnus Fries in 1861. Arctomia has a circumpolar distribution.

Species

Molecular phylogenetic evidence revealed inappropriate classifications for two species once placed in this genus, A. insignis (P.M.Jørg. & Tønsberg) Ertz and A. borbonica Magain & Sérus.; they were formally transferred to the genus Gabura in 2020. Arctomia fascicularis (L.) Otálora & Wedin (2013) was confirmed to belong to Gabura, a generic placement originally proposed by Per Magnus Jørgensen in 2014.