| Millennium: | 1st millennium BC |
|---|---|
| Centuries: | 2nd century BC – 1st century BC – 1st century |
| Decades: | 120s BC 110s BC 100s BC – 90s BC – 80s BC 70s BC 60s BC |
| Years: | 102 BC 101 BC 100 BC – 99 BC – 98 BC 97 BC 96 BC |
| 99 BC by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishments and disestablishments categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 99 BC |
| Ab urbe condita | 655 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1942 – -1941 |
| Bengali calendar | -691 |
| Berber calendar | 852 |
| Buddhist calendar | 446 |
| Burmese calendar | -736 |
| Byzantine calendar | 5410 – 5411 |
| Chinese calendar | [[Sexagenary cycle|]]年 (2538/2598) — to —
[[Sexagenary cycle|]]年(2539/2599) |
| Coptic calendar | -382 – -381 |
| Ethiopian calendar | -106 – -105 |
| Hebrew calendar | 3662 – 3663 |
| Hindu calendars | |
| - Bikram Samwat | -42 – -41 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3003 – 3004 |
| Holocene calendar | 9902 |
| Iranian calendar | 720 BP – 719 BP |
| Islamic calendar | 742 BH – 741 BH |
| Japanese calendar | |
| Korean calendar | 2235 |
| Thai solar calendar | 445 |
Year 99 BC was a year of the pre-Julian calendar.