| Millennium: | 1st millennium |
|---|---|
| Centuries: | 8th century – 9th century – 10th century |
| Decades: | 820s 830s 840s – 850s – 860s 870s 880s |
| Years: | 854 855 856 – 857 – 858 859 860 |
| 857 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 857 DCCCLVII |
| Ab urbe condita | 1610 |
| Armenian calendar | 306 ԹՎ ՅԶ |
| Assyrian calendar | 5607 |
| Bahá'í calendar | -987–-986 |
| Bengali calendar | 264 |
| Berber calendar | 1807 |
| English Regnal year | N/A |
| Buddhist calendar | 1401 |
| Burmese calendar | 219 |
| Byzantine calendar | 6365–6366 |
| Chinese calendar | 丙子年十二月初二日 (3493/3553-12-2) — to —
丁丑年十二月十二日(3494/3554-12-12) |
| Coptic calendar | 573–574 |
| Ethiopian calendar | 849–850 |
| Hebrew calendar | 4617–4618 |
| Hindu calendars | |
| - Vikram Samvat | 913–914 |
| - Shaka Samvat | 779–780 |
| - Kali Yuga | 3958–3959 |
| Holocene calendar | 10857 |
| Iranian calendar | 235–236 |
| Islamic calendar | 242–243 |
| Japanese calendar | |
| Korean calendar | 3190 |
| Minguo calendar | 1055 before ROC 民前1055年 |
| Thai solar calendar | 1400 |
Year 857 (DCCCLVII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.