| Millennium: | 2nd millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 1251 by topic |
|---|
| Leaders |
| Birth and death categories |
| Births – Deaths |
| Establishments and disestablishments categories |
| Establishments – Disestablishments |
| Art and literature |
| 1251 in poetry |
| Gregorian calendar | 1251 MCCLI |
| Ab urbe condita | 2004 |
| Armenian calendar | 700 ԹՎ Չ |
| Assyrian calendar | 6001 |
| Balinese saka calendar | 1172–1173 |
| Bengali calendar | 658 |
| Berber calendar | 2201 |
| English Regnal year | 35 Hen. 3 – 36 Hen. 3 |
| Buddhist calendar | 1795 |
| Burmese calendar | 613 |
| Byzantine calendar | 6759–6760 |
| Chinese calendar | 庚戌年 (Metal Dog) 3948 or 3741 — to — 辛亥年 (Metal Pig) 3949 or 3742 |
| Coptic calendar | 967–968 |
| Discordian calendar | 2417 |
| Ethiopian calendar | 1243–1244 |
| Hebrew calendar | 5011–5012 |
| Hindu calendars | |
| - Vikram Samvat | 1307–1308 |
| - Shaka Samvat | 1172–1173 |
| - Kali Yuga | 4351–4352 |
| Holocene calendar | 11251 |
| Igbo calendar | 251–252 |
| Iranian calendar | 629–630 |
| Islamic calendar | 648–649 |
| Japanese calendar | Kenchō 3 (建長３年) |
| Javanese calendar | 1160–1161 |
| Julian calendar | 1251 MCCLI |
| Korean calendar | 3584 |
| Minguo calendar | 661 before ROC 民前661年 |
| Nanakshahi calendar | −217 |
| Thai solar calendar | 1793–1794 |
| Tibetan calendar | 阳金狗年 (male Iron-Dog) 1377 or 996 or 224 — to — 阴金猪年 (female Iron-Pig) 1378 or 997 or 225 |
Year 1251 (MCCLI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar.