| Years |
|---|
| Millennium |
| 2nd millennium |
| Centuries |
| Decades |
| Years |
| Gregorian calendar | 1451 MCDLI |
| Ab urbe condita | 2204 |
| Armenian calendar | 900 ԹՎ Ջ |
| Assyrian calendar | 6201 |
| Balinese saka calendar | 1372–1373 |
| Bengali calendar | 858 |
| Berber calendar | 2401 |
| English Regnal year | 29 Hen. 6 – 30 Hen. 6 |
| Buddhist calendar | 1995 |
| Burmese calendar | 813 |
| Byzantine calendar | 6959–6960 |
| Chinese calendar | 庚午年 (Metal Horse) 4147 or 4087 — to — 辛未年 (Metal Goat) 4148 or 4088 |
| Coptic calendar | 1167–1168 |
| Discordian calendar | 2617 |
| Ethiopian calendar | 1443–1444 |
| Hebrew calendar | 5211–5212 |
| Hindu calendars | |
| - Vikram Samvat | 1507–1508 |
| - Shaka Samvat | 1372–1373 |
| - Kali Yuga | 4551–4552 |
| Holocene calendar | 11451 |
| Igbo calendar | 451–452 |
| Iranian calendar | 829–830 |
| Islamic calendar | 854–855 |
| Japanese calendar | Hōtoku 3 (宝徳3年) |
| Javanese calendar | 1366–1367 |
| Julian calendar | 1451 MCDLI |
| Korean calendar | 3784 |
| Minguo calendar | 461 before ROC 民前461年 |
| Nanakshahi calendar | −17 |
| Thai solar calendar | 1993–1994 |
| Tibetan calendar | ལྕགས་ཕོ་རྟ་ལོ་ (male Iron-Horse) 1577 or 1196 or 424 — to — ལྕགས་མོ་ལུག་ལོ་ (female Iron-Sheep) 1578 or 1197 or 425 |
1451 (MCDLI) was a common year starting on Friday of the Julian calendar, the 1451st year of the Common Era (CE) and Anno Domini (AD) designations, the 451st year of the 2nd millennium, the 51st year of the 15th century, and the 2nd year of the 1450s decade. As of the start of 1451, the Gregorian calendar was 9 days ahead of the Julian calendar, which was the dominant calendar of the time.