| Years |
|---|
| Millennium |
| 2nd millennium |
| Centuries |
| Decades |
| Years |
| Gregorian calendar | 1266 MCCLXVI |
| Ab urbe condita | 2019 |
| Armenian calendar | 715 ԹՎ ՉԺԵ |
| Assyrian calendar | 6016 |
| Balinese saka calendar | 1187–1188 |
| Bengali calendar | 673 |
| Berber calendar | 2216 |
| English Regnal year | 50 Hen. 3 – 51 Hen. 3 |
| Buddhist calendar | 1810 |
| Burmese calendar | 628 |
| Byzantine calendar | 6774–6775 |
| Chinese calendar | 乙丑年 (Wood Ox) 3962 or 3902 — to — 丙寅年 (Fire Tiger) 3963 or 3903 |
| Coptic calendar | 982–983 |
| Discordian calendar | 2432 |
| Ethiopian calendar | 1258–1259 |
| Hebrew calendar | 5026–5027 |
| Hindu calendars | |
| - Vikram Samvat | 1322–1323 |
| - Shaka Samvat | 1187–1188 |
| - Kali Yuga | 4366–4367 |
| Holocene calendar | 11266 |
| Igbo calendar | 266–267 |
| Iranian calendar | 644–645 |
| Islamic calendar | 664–665 |
| Japanese calendar | Bun'ei 3 (文永３年) |
| Javanese calendar | 1176–1177 |
| Julian calendar | 1266 MCCLXVI |
| Korean calendar | 3599 |
| Minguo calendar | 646 before ROC 民前646年 |
| Nanakshahi calendar | −202 |
| Thai solar calendar | 1808–1809 |
| Tibetan calendar | ཤིང་མོ་གླང་ལོ་ (female Wood-Ox) 1392 or 1011 or 239 — to — མེ་ཕོ་སྟག་ལོ་ (male Fire-Tiger) 1393 or 1012 or 240 |
1266 (MCCLXVI) was a common year starting on Friday of the Julian calendar, the 1266th year of the Common Era (CE) and Anno Domini (AD) designations, the 266th year of the 2nd millennium, the 66th year of the 13th century, and the 7th year of the 1260s decade. As of the start of 1266, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.