Adenovirus infection occurs globally in the form of sporadic cases and isolated outbreaks. Human adenovirus type 55 (HAdV-55), endemic in China and South Korea, causes acute respiratory viral infections (ARVI) of varying severity, both among the civilian population and in military units in different countries of the world. Genomic research facilitates reliable identification of HAdV-55. The aim of this study was to identify HAdV isolated in Moscow in 2022, as well as to conduct whole-genome sequencing and comparative genomic research.HAdV-55 was isolated from a sample of a patient hospitalized with pneumonia and analyzed using restriction fragment length polymorphism analysis and whole-genome sequencing. Bioinformatics comparative analysis was performed on a sample of sequences of 83 isolates.The whole-genome sequencing of first isolated in Russia HAdV-55 was conducted. The sequence of isolate SCV3008:Ad55 was deposited in GenBank (Accession Number PQ641625). Unique mutations in the SCV3008:Ad55 genome were identified, one of which resulted in a conservative T29A substitution in the penton that did not affect its functions. Phylogenetic analysis showed clustering of SCV3008:Ad55 with isolates of clade II, which included representatives of 7 countries on different continents, indicating a wide distribution of HAdV-55. Isolates from endemic regions of China and South Korea formed separate clades. The study of microsatellite length polymorphism in untranslated regions of the genome became an additional tool for distinguishing closely related genomes.The obtained genomic information laid the foundation for further monitoring for HAdV-55 in Russia and demonstrated the informativeness and significance of whole-genome studies for monitoring adenoviruses. The development and implementation of genotyping methods aimed at detecting HAdV-55 and other clinically relevant genotypes will significantly improve the effectiveness of the diagnosis of adenovirus infections with the threat of developing bronchopneumonia.