| Millennium: | 1st millennium |
|---|---|
| Centuries: | 2nd century – 3rd century – 4th century |
| Decades: | 220s 230s 240s – 250s – 260s 270s 280s |
| Years: | 254 255 256 – 257 – 258 259 260 |
| 257 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 257 CCLVII |
| Ab urbe condita | 1010 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1587 – -1586 |
| Bengali calendar | -336 |
| Berber calendar | 1207 |
| Buddhist calendar | 801 |
| Burmese calendar | -381 |
| Byzantine calendar | 5765 – 5766 |
| Chinese calendar | 丙子年十一月廿九日 (2893/2953-11-29) — to —
丁丑年十一月初九日(2894/2954-11-9) |
| Coptic calendar | -27 – -26 |
| Ethiopian calendar | 249 – 250 |
| Hebrew calendar | 4017 – 4018 |
| Hindu calendars | |
| - Bikram Samwat | 313 – 314 |
| - Shaka Samvat | 179 – 180 |
| - Kali Yuga | 3358 – 3359 |
| Holocene calendar | 10257 |
| Iranian calendar | 365 BP – 364 BP |
| Islamic calendar | 376 BH – 375 BH |
| Japanese calendar | |
| Korean calendar | 2590 |
| Thai solar calendar | 800 |