We conducted the first comprehensive floristic study of the lichens and allied fungi of Salmonier Nature Park on the Avalon Peninsula in Newfoundland, Canada. By comparing our results to those from other provincial parks in Newfoundland, we show that Salmonier Nature Park has a regionally rich lichen biota that includes several uncommon species. We carry out an assessment of landscape-level drivers including geographic location and land cover diversity to determine whether lichen richness corresponds to patterns at the landscape extent. Within Salmonier, one species (Erioderma pedicellatum) is listed as “special concern” by the federal Committee on the Status of Endangered Wildlife in Canada and “critically endangered” by the International Union for Conservation of Nature. Two species are new to the island of Newfoundland: Phaeophyscia ciliata and Stereocaulon subcoralloides. Six species are new to the province of Newfoundland and Labrador: Ephebe hispidula, Muellerella lichenicola, Mycoblastus sanguinarioides, Placynthium flabellosum, Usnea flammea, and Xanthoparmelia angustiphylla. Our results provide baseline knowledge that allows changes in the lichen community to be monitored, the discovery of new species in the park to be acknowledged, regional distributions and frequencies to be better understood, and accurate comparisons to be made with other parks.