Ten lichen species: Buellia miriquidica, Catillaria contristans, Fuscidea gothoburgensis, Hymenelia cyanocarpa, Lecanora caesiosora, “Lecidea” commaculans, Metamelanea umbonata, Micarea coppinsii, M. marginata and Stereocaulon plicatile are reported for the first time for North America from Mt. Katahdin, Maine. A further 22 taxa for which the Mt. Katahdin records represent a significant extension of their range on the continent, mostly being first reports from either eastern North America or the contiguous United States, are also reported.