[in Russian with English abstract: ] A new cyanobacterium species Stigonema lichenoides Patova, Novakovskaya, Shalygin et Shadrin, sp. nov., a photobiont of the cyanolichen Ephebe lanata, has been described. The samples were collected from rocky substrates in the mountain tundra of the Northern Urals. A detailed morphological description is given and differences between this species and related taxa of the genus Stigonema are discussed. A molecular phylogenetic analysis of the studied samples was performed using 16S–23S rRNA sequences. The correlation of morphological and molecular data, as well as the comparison of the sequences obtained from the samples with data available in the NCBI database, allowed the identification of a new species of the genus Stigonema. Keywords: Cyanobacteriota, Cyanophyta, Stigonema, morphology, phylogeny, cyanobiont, Northern Urals, Russia.