| Millennium: | 1st millennium BC |
|---|---|
| Centuries: | 2nd century BC – 1st century BC – 1st century |
| Decades: | 70s BC 60s BC 50s BC – 40s BC – 30s BC 20s BC 10s BC |
| Years: | 48 BC 47 BC 46 BC – 45 BC – 44 BC 43 BC 42 BC |
| 45 BC by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishments and disestablishments categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 45 BC |
| Ab urbe condita | 709 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1888 – -1887 |
| Bengali calendar | -637 |
| Berber calendar | 906 |
| Buddhist calendar | 500 |
| Burmese calendar | -682 |
| Byzantine calendar | 5464 – 5465 |
| Chinese calendar | 乙亥年 (2592/2652) — to —
丙子年(2593/2653) |
| Coptic calendar | -328 – -327 |
| Ethiopian calendar | -52 – -51 |
| Hebrew calendar | 3716 – 3717 |
| Hindu calendars | |
| - Bikram Samwat | 12 – 13 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3057 – 3058 |
| Holocene calendar | 9956 |
| Iranian calendar | 666 BP – 665 BP |
| Islamic calendar | 686 BH – 685 BH |
| Japanese calendar | |
| Korean calendar | 2289 |
| Thai solar calendar | 499 |
Year 45 BC was a leap year starting on Friday (link will display the full calendar) and the first year of the Julian calendar. At the time, it was known as the Year of the Consulship of Caesar without Colleague (or, less frequently, year 709 Ab urbe condita). The denomination 45 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.