This study investigates the Agrippesioi and Augustesioi synagogues of ancient Rome. Known from inscriptions found primarily in the Monteverde Catacombs, the synagogues are conventionally dated to the first century CE. Common opinion is that they were named directly after Marcus Agrippa and the emperor Augustus, both of whom, it is thought, played some part in founding the synagogues. Based on the chronology of the catacombs and the inscriptions, I assign the synagogues to the third and fourth centuries. Taking into account the linguistic and epigraphic comparanda of that period, I argue that the synagogue names were toponyms. They signaled where in Rome the Jewish synagogues were. The analysis has further implications for the history and social setting of Roman Jews. Like other groups at the time, they were identifying themselves based on areas or features in the late antique urban landscape that had been associated with Agrippa and Augustus for centuries.