| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 20s 30s 40s – 50s – 60s 70s 80s |
| Years: | 48 49 50 – 51 – 52 53 54 |
| 51 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 51 LI |
| Ab urbe condita | 804 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1793 – -1792 |
| Bengali calendar | -542 |
| Berber calendar | 1001 |
| Buddhist calendar | 595 |
| Burmese calendar | -587 |
| Byzantine calendar | 5559 – 5560 |
| Chinese calendar | 庚戌年十一月三十日 (2687/2747-11-30) — to —
辛亥年十一月初十日(2688/2748-11-10) |
| Coptic calendar | -233 – -232 |
| Ethiopian calendar | 43 – 44 |
| Hebrew calendar | 3811 – 3812 |
| Hindu calendars | |
| - Bikram Samwat | 107 – 108 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3152 – 3153 |
| Holocene calendar | 10051 |
| Iranian calendar | 571 BP – 570 BP |
| Islamic calendar | 589 BH – 588 BH |
| Japanese calendar | |
| Korean calendar | 2384 |
| Thai solar calendar | 594 |
Year 51 (LI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.