| Centuries: | 4th century · 5th century · 6th century |
| Decades: | 420s 430s 440s 450s 460s 470s 480s |
| Years: | 448 449 450 451 452 453 454 |
| 451 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 451 CDLI |
| Ab urbe condita | 1204 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1393 – -1392 |
| Bengali calendar | -142 |
| Berber calendar | 1401 |
| Buddhist calendar | 995 |
| Burmese calendar | -187 |
| Byzantine calendar | 5959 – 5960 |
| Chinese calendar | 庚寅年十一月十三日 (3087/3147-11-13) — to —
辛卯年十一月廿三日(3088/3148-11-23) |
| Coptic calendar | 167 – 168 |
| Ethiopian calendar | 443 – 444 |
| Hebrew calendar | 4211 – 4212 |
| Hindu calendars | |
| - Bikram Samwat | 507 – 508 |
| - Shaka Samvat | 373 – 374 |
| - Kali Yuga | 3552 – 3553 |
| Holocene calendar | 10451 |
| Iranian calendar | 171 BP – 170 BP |
| Islamic calendar | 176 BH – 175 BH |
| Japanese calendar | |
| Korean calendar | 2784 |
| Thai solar calendar | 994 |