An intensive lichen biodiversity inventory of the imperiled Mid-Atlantic Coastal Plain of eastern North America resulted in the discovery of a new species of the ecologically sensitive macrolichen genus Sticta. The species is formally described as S. deyana based on a combination of molecular and morphological data. It is most similar to the southern Appalachian endemic S. fragilinata, differing in its diminutive thallus, narrower lobes, and allopatric distribution. All but one population of S. deyana occurs within the Dare Regional Biodiversity Hotspot of coastal North Carolina and within the most conservative estimated sea-level rise by 2100.