We collected 209 Ixodes persulcatus ticks in various regions of Russia, including the southern Urals and western and eastern Siberia. Using PCR amplification and sequencing of the citrate synthase-encoding gene (gltA), we detected a new rickettsial genotype, which we named "Candidatus Rickettsia tarasevichiae." This bacterium was found in 9.27%, 10.0%, and 20.5% of the ticks collected in western Siberia, eastern Siberia, and the southern Urals, respectively. "Candidatus Rickettsia tarasevichiae" exhibited a 98% and 96% nucleotide sequence homology, with the 16S rDNA and gltA sequence, respectively, of R. canadensis, a rickettsia previously only found in Haemaphysalis leporispalustris ticks in North America. The phylogenetic analysis of "Candidatus Rickettsia tarasevichiae" and other Rickettsia species allowed the creation of a new cluster with high bootstrap values within the Rickettsia genus involving this rickettsia, R. canadensis, and three uncultured rickettsiae from plant insects.