Year 103 (CIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Traianus and Maximus (or, less frequently, year 856 Ab urbe condita). The denomination 103 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.

• Sextus Iulius Frontinus, römischer Senator, Soldat und Schriftsteller (* um 40)

Denna artikel handlar om året 103. För talet med samma namn, se 103 (tal).

103 (CIII) var ett normalår som började en söndag i den julianska kalendern.