The first checklist of lichens occurring in the Ujście Warty National Park and its buffer zone is presented. The list is based primarily on the research conducted in years 2022–2024, but incorporates also the earlier literature data. During the research 138 lichen taxa were recorded, including 122 within the boundaries of the national park and 81 in its buffer zone. They represent various habitat groups: epiphytes (63 species), epixyles (59 species), epigeits (31 species), epiliths (39 species, both calcicolous and silicicolous) and species found on metal (20 species). A characteristic feature of the analysed lichen biota is the dominance of taxa typical of highly eutrophic habitats. Keywords: protected area; biodiversity; species richness; Western Poland; lichenized Ascomycota.