| Millennium: | 1st millennium BC |
|---|---|
| Centuries: | 2nd century BC – 1st century BC – 1st century |
| Decades: | 110s BC 100s BC 90s BC – 80s BC – 70s BC 60s BC 50s BC |
| Years: | 89 BC 88 BC 87 BC – 86 BC – 85 BC 84 BC 83 BC |
| 86 BC by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishments and disestablishments categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 86 BC |
| Ab urbe condita | 668 |
| Armenian calendar | N/A |
| Assyrian calendar | 4665 |
| Bahá'í calendar | -1929–-1928 |
| Bengali calendar | -678 |
| Berber calendar | 865 |
| English Regnal year | N/A |
| Buddhist calendar | 459 |
| Burmese calendar | -723 |
| Byzantine calendar | 5423–5424 |
| Chinese calendar | 甲午年 (2551/2611) — to —
乙未年(2552/2612) |
| Coptic calendar | -369–-368 |
| Ethiopian calendar | -93–-92 |
| Hebrew calendar | 3675–3676 |
| Hindu calendars | |
| - Vikram Samvat | -29–-28 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3016–3017 |
| Holocene calendar | 9915 |
| Iranian calendar | 707 BP – 706 BP |
| Islamic calendar | 729 BH – 728 BH |
| Japanese calendar | |
| Korean calendar | 2248 |
| Minguo calendar | 1997 before ROC 民前1997年 |
| Thai solar calendar | 458 |
Year 86 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Cinna and Marius/Flaccus (or, less frequently, year 668 Ab urbe condita). The denomination 86 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.