|Millennium:||1st millennium BC|
|13 BC by topic|
|Gregorian calendar||13 BC|
|Ab urbe condita||741|
|Ancient Greek era||191st Olympiad, year 4|
|Balinese saka calendar||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||3088–3089|
|Iranian calendar||634 BP – 633 BP|
|Islamic calendar||654 BH – 652 BH|
|Julian calendar||13 BC|
|Minguo calendar||1924 before ROC|
|Seleucid era||299/300 AG|
|Thai solar calendar||530–531|
114 or −267 or −1039
— to —
115 or −266 or −1038
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.
- Aemilius Lepidus Paullus, member of the Roman Senate (approximate date) (b. c. 77 BC)
- Marcus Aemilius Lepidus, triumvir (b. c. 90 BC)