| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 50s 60s 70s – 80s – 90s 100s 110s |
| Years: | 78 79 80 – 81 – 82 83 84 |
| 81 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 81 LXXXI |
| Ab urbe condita | 834 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1763 – -1762 |
| Bengali calendar | -512 |
| Berber calendar | 1031 |
| Buddhist calendar | 625 |
| Burmese calendar | -557 |
| Byzantine calendar | 5589 – 5590 |
| Chinese calendar | 庚辰年十二月初二日 (2717/2777-12-2) — to —
辛巳年十一月十二日(2718/2778-11-12) |
| Coptic calendar | -203 – -202 |
| Ethiopian calendar | 73 – 74 |
| Hebrew calendar | 3841 – 3842 |
| Hindu calendars | |
| - Bikram Samwat | 137 – 138 |
| - Shaka Samvat | 3 – 4 |
| - Kali Yuga | 3182 – 3183 |
| Holocene calendar | 10081 |
| Iranian calendar | 541 BP – 540 BP |
| Islamic calendar | 558 BH – 557 BH |
| Japanese calendar | |
| Korean calendar | 2414 |
| Thai solar calendar | 624 |
Year 81 (LXXXI) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.