Coelocladia arctica is a small crustose to subsquamulose lichen in the family Cladoniaceae (or Stereocaulaceae, depending on classification), characterised by its occurrence in arctic and subarctic environments across the circumpolar north. As an arctic lichen, it typically forms low-growing, pale greyish-green to whitish thalli on exposed mineral soils, rocky substrates, and acidic tundra, where it contributes to the biocrust communities that stabilise fragile northern soils and play roles in nitrogen fixation and carbon sequestration. Lichens are composite organisms formed by the symbiotic association of a fungal partner (mycobiont) and one or more photosynthetic partners (algae or cyanobacteria), and Coelocladia arctica represents this intimate ecological partnership adapted to some of the most extreme growing conditions on Earth—including freeze-thaw cycles, desiccation, and prolonged snow cover. Distribution records for this species extend across Greenland, Iceland, Svalbard, northern Norway, and other circumpolar arctic territories, reflecting adaptation to cold continental and maritime tundra climates. Arctic lichens such as this species are considered sensitive indicators of climate change, as warming temperatures shift competitive balances in tundra plant communities and alter snowpack dynamics that influence lichen growth periods. No formal IUCN conservation assessment has been conducted for this species.