In the article, on the basis of the discovered sites, new areas of the Roman garrison location are revealed, in the form of seven barracks (contubernia), which were added to the defensive wall and tower at the Lower city of Olbia Pontica. At the lateral quarter, which belonged to the Roman officer, there were found marble bases of the internal columns with the name of the centurion M. Emilius Severinus of the Legio I Italica. The architectural complex located to the south of the barracks in its layout resembles administrative buildings of the Roman camps like a principia – the officers’ house, which consisted of a number of rooms located along the perimeter around the courtyard: with a separate kitchen, a dining room, a central sanctuary room (aedes principiorum), where were stored legionary signs (signa militaria), altars, and statues of deities and emperors. This can be evidenced by the architectural details found during the excavations, terracotta in the shape of eagles and Roman soldiers, Roman weapons and equipment. A similar arrangement of barracks in Olbia is known on the citadel, under the Northern defensive wall. The problem of interpretation of the praetorium building in Olbia is also considered, some quarters of which could serve as Roman barracks. The construction of the barrack blocks and headquarters buildings can be attributed to the second half of the 2nd century AD – the time of the stationary Roman garrison appearance in Olbia.