Paanajärvi National Park (NP), located in the northwestern part of the Republic of Karelia, is characterized by a low-mountain landscape with the southernmost tundra in Eastern Fennoscandia, a predominance of forest vegetation, and high biodiversity with a large number of specific flora and fauna species. Lichenological research in the national park began in the late 19th century, done by Finnish botanists. A checklist of 436 lichen species was published in the late 20th century. Since then, no targeted study of the lichen diversity in the Paanajärvi NP has been carried out. In 2024–2025, the lichen species diversity was studied within 19 sample plots (625 m2 each) were established in three altitudinal zones: forest, forest-tundra, and tundra. The paper presents a list of 87 species of lichens and allied fungi found for the first time in the park, including 74 species recorded for the Regio kuusamoënsis biogeographic province. Two species, Bryoria nitidula and Chaenotheca phaeocephala, are listed in the Red Data Book of the Republic of Karelia (2020). The records of Micarea adnata and Rhizocarpon simillimum are their second occurrence in Karelia. Most of the species are widespread in boreal communities. Among the identified lichen groups, epiphytes predominate (48 %), followed by eurytopic species (25 %), and obligate terricolous species (5 %). Lichens of the epixylic and epilithic ecological groups account for no more than 11 % of the total number of species discovered. Totally, 548 species of lichens and allied fungi are currently known for the territory of the Paanajärvi NP.