1266
| Years | 
|---|
| Millennium | 
| 2nd millennium | 
| Centuries | 
| Decades | 
| Years | 
| 1266 by topic | 
|---|
| Leaders | 
| 
 | 
| Birth and death categories | 
| Births – Deaths | 
| Establishments and disestablishments categories | 
| Establishments – Disestablishments | 
| Art and literature | 
| 1266 in poetry | 
| Gregorian calendar | 1266 MCCLXVI | 
| Ab urbe condita | 2019 | 
| Armenian calendar | 715 ԹՎ ՉԺԵ | 
| Assyrian calendar | 6016 | 
| Balinese saka calendar | 1187–1188 | 
| Bengali calendar | 672–673 | 
| 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) 3963 or 3756 — to — 丙寅年 (Fire Tiger) 3964 or 3757 | 
| 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 | 阴木牛年 (female Wood-Ox) 1392 or 1011 or 239 — to — 阳火虎年 (male Fire-Tiger) 1393 or 1012 or 240 | 
Year 1266 (MCCLXVI) was a common year starting on Friday of the Julian calendar.