| Millennium: | 1st millennium BC |
|---|---|
| Centuries: | 2nd century BC – 1st century BC – 1st century |
| Decades: | 30s BC 20s BC 10s BC – 0s BC – 0s 10s 20s |
| Years: | 6 BC 5 BC 4 BC – 3 BC – 2 BC 1 BC 1 AD |
| 3 BC by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishments and disestablishments categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 3 BC |
| Ab urbe condita | 751 |
| Armenian calendar | N/A |
| Assyrian calendar | 4748 |
| Bahá'í calendar | -1846–-1845 |
| Bengali calendar | -595 |
| Berber calendar | 948 |
| English Regnal year | N/A |
| Buddhist calendar | 542 |
| Burmese calendar | -640 |
| Byzantine calendar | 5506–5507 |
| Chinese calendar | 丁巳年 (2634/2694) — to —
戊午年(2635/2695) |
| Coptic calendar | -286–-285 |
| Ethiopian calendar | -10–-9 |
| Hebrew calendar | 3758–3759 |
| Hindu calendars | |
| - Vikram Samvat | 54–55 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3099–3100 |
| Holocene calendar | 9998 |
| Iranian calendar | 624 BP – 623 BP |
| Islamic calendar | 643 BH – 642 BH |
| Japanese calendar | |
| Korean calendar | 2331 |
| Minguo calendar | 1914 before ROC 民前1914年 |
| Thai solar calendar | 541 |
Year 3 BC was a common year starting on Wednesday or Thursday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Tuesday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Lentulus and Messalla (or, less frequently, year 751 Ab urbe condita). The denomination 3 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.