|203 by topic|
|Ab urbe condita||956|
|Balinese saka calendar||124–125|
|Chinese calendar||壬午年 (Water Horse)|
2899 or 2839
— to —
癸未年 (Water Goat)
2900 or 2840
|Coptic calendar||−81 – −80|
|- Vikram Samvat||259–260|
|- Shaka Samvat||124–125|
|- Kali Yuga||3303–3304|
|Iranian calendar||419 BP – 418 BP|
|Islamic calendar||432 BH – 431 BH|
|Minguo calendar||1709 before ROC|
|Seleucid era||514/515 AG|
|Thai solar calendar||745–746|
329 or −52 or −824
— to —
330 or −51 or −823
Year 203 (CCIII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Plautianus and Geta (or, less frequently, year 956 Ab urbe condita). The denomination 203 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.
- Emperor Septimius Severus rebuilds Byzantium, and expands the southern frontier of Africa, with the metropolis Carthage re-fortified.
- Gaius Fulvius Plautianus and Publius Septimius Geta become Roman Consuls.
- An arch dedicated to Septimius Severus is erected near the Forum.
- The Portico of Octavia is reconstructed.
- Prince Vijaya becomes king of the Andhra Empire. During his reign, the empire is broken apart into smaller independent principalities.
- Battle of Xiakou: Warlord Sun Quan battles his rival Huang Zu along the Yangtze River near Wuhan.
- Origen of Alexandria replaces Clement as the head of the Christian school in Alexandria.
- Eulpaso, Korean official and Prime-Minister
- Ling Cao, Chinese general under Sun Ce
- Perpetua and Felicity, Christian martyrs
- Sun Yi, Chinese general and politician (b. 184)
- Wu Jing, Chinese general under Sun Ce
- ^ Birley, Anthony R. (1999). Septimius Severus: The African Emperor, p. 153. London: Routledge. ISBN 978-0-415-16591-4.