We present an updated checklist for Konevets Island (Leningrad Region, Russia). The revealed lichen biota comprises 435 species, including 378 lichens, 46 lichenicolous fungi and 11 non-lichenized saprobic fungi, of which 31 species (27 lichens and 4 lichenicolous fungi) are known only from collections made by Veli Räsänen (1917, 1938). Acremonium hypholomatis is reported for the first time for Russia; Caloplaca soralifera, Trapelia corticola, and Muellerella lichenicola for Northwestern European Russia; and Bacidia vermifera, Lecanora mughicola, Micarea contexta, Pyrenochaeta xanthoriae, Rhizocarpon disporum, Stigmidium squamariae and Xylographa difformis for Leningrad Region. From lichenological point of view, the most valuable habitats of Konevets Island are old-growth spruce forests. The studied lichen biota is rich and diverse and exceptionally well-preserved in comparison to the mainland part of Karelian Isthmus. It definitely deserves protection.