The paper presents data on 18 lichen species registered on Shikotan Island for the first time, including Bryobilimbia hypnorum, Heterodermia incana, Physconia hokkaidensis, new for the Kuril Isles, and Chaenotheca ferruginea, P. propaguliferum, new for Sakhalin Oblast. Seven species (Anzia opuntiella, Coccocarpia erythroxyli, Collema japonicum, Heterodermia incana, Megalospora atrorubricans subsp. sendaiensis, Polyblastidium japonicum, and P. propaguliferum) are rare; one (Coccocarpia erythroxyli) has a conservation status in the Red Books of Sakhalin Oblast and of the Russian Federation. Brief information on distribution, ecology, essences, and contents of secondary metabolites as well as locations and photos are presented for the species.