|Millennium:||1st millennium BC|
|Centuries:||2nd century BC – 1st century BC – 1st century|
|Decades:||40s BC 30s BC 20s BC – 10s BC – 0s BC 0s 10s|
|Years:||16 BC 15 BC 14 BC – 13 BC – 12 BC 11 BC 10 BC|
|13 BC by topic|
|Gregorian calendar||13 BC|
|Ab urbe condita||741|
|Bahá'í calendar||−1856 – −1855|
|English Regnal year||N/A|
|Chinese calendar||丁未年 (Fire Goat)
2684 or 2624
— to —
戊申年 (Earth Monkey)
2685 or 2625
|Coptic calendar||−296 – −295|
|Ethiopian calendar||−20 – −19|
|- Vikram Samvat||44–45|
|- Shaka Samvat||N/A|
|- Kali Yuga||3089–3090|
|Igbo calendar||−1012 – −1011|
|Iranian calendar||634 BP – 633 BP|
|Islamic calendar||654 BH – 652 BH|
|Julian calendar||13 BC|
|Minguo calendar||1924 before ROC
|Thai solar calendar||531|
|Wikimedia Commons has media related to 13 BC.|
Year 13 BC was either a common year starting on Friday, Saturday or Sunday or a leap year starting on Friday or Saturday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a leap year starting on Wednesday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Nero and Varus (or, less frequently, year 741 Ab urbe condita). The denomination 13 BC 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.
- Tiberius Claudius Nero and Publius Quinctilius Varus are Roman Consuls.
- The Roman general Nero Claudius Drusus builds the stronghold of castrum Moguntiacum, the modern city of Mainz, Germany.
- Drusus is granted governor of Gaul and mobilized a Roman army to beat the Germans back across the Rhine. He traveled to the North Sea and pays tribute to the Frisii.
- The Ara Pacis Augustae ("Altar of Augustan Peace"), is commissioned by the Roman Senate to honor the triumphal return of emperor Augustus from Hispania and Gaul.
- Revolt in Thrace against Roman rule led by Vologaeses.