| Millennium: | 2nd millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 1666 by topic |
|---|
| Arts and science |
| Leaders |
| Birth and death categories |
| Births – Deaths |
| Establishments and disestablishments categories |
| Establishments – Disestablishments |
| Works category |
| Gregorian calendar | 1666 MDCLXVI |
| Ab urbe condita | 2419 |
| Armenian calendar | 1115 ԹՎ ՌՃԺԵ |
| Assyrian calendar | 6416 |
| Balinese saka calendar | 1587–1588 |
| Bengali calendar | 1073 |
| Berber calendar | 2616 |
| English Regnal year | 17 Cha. 2 – 18 Cha. 2 |
| Buddhist calendar | 2210 |
| Burmese calendar | 1028 |
| Byzantine calendar | 7174–7175 |
| Chinese calendar | 乙巳年 (Wood Snake) 4363 or 4156 — to — 丙午年 (Fire Horse) 4364 or 4157 |
| Coptic calendar | 1382–1383 |
| Discordian calendar | 2832 |
| Ethiopian calendar | 1658–1659 |
| Hebrew calendar | 5426–5427 |
| Hindu calendars | |
| - Vikram Samvat | 1722–1723 |
| - Shaka Samvat | 1587–1588 |
| - Kali Yuga | 4766–4767 |
| Holocene calendar | 11666 |
| Igbo calendar | 666–667 |
| Iranian calendar | 1044–1045 |
| Islamic calendar | 1076–1077 |
| Japanese calendar | Kanbun 6 (寛文６年) |
| Javanese calendar | 1588–1589 |
| Julian calendar | Gregorian minus 10 days |
| Korean calendar | 3999 |
| Minguo calendar | 246 before ROC 民前246年 |
| Nanakshahi calendar | 198 |
| Thai solar calendar | 2208–2209 |
| Tibetan calendar | 阴木蛇年 (female Wood-Snake) 1792 or 1411 or 639 — to — 阳火马年 (male Fire-Horse) 1793 or 1412 or 640 |
1666 (MDCLXVI) was a common year starting on Friday of the Gregorian calendar and a common year starting on Monday of the Julian calendar, the 1666th year of the Common Era (CE) and Anno Domini (AD) designations, the 666th year of the 2nd millennium, the 66th year of the 17th century, and the 7th year of the 1660s decade. As of the start of 1666, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.
This is the first year to be designated as an Annus mirabilis, in John Dryden's 1667 poem so titled, celebrating England's failure to be beaten either by the Dutch or by fire.