Year 345 (CCCXLV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Amantius and Albinus (or, less frequently, year 1098 Ab urbe condita). The denomination 345 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

345 (CCCXLV) var ett normalår som började en tisdag i den julianska kalendern.