|Centuries:||16th century – 17th century – 18th century|
|Decades:||1630s 1640s 1650s – 1660s – 1670s 1680s 1690s|
|Years:||1663 1664 1665 – 1666 – 1667 1668 1669|
|1666 by topic:|
|Arts and Science|
|Architecture - Art - Literature - Music - Science|
|Lists of leaders|
|Colonial governors - State leaders|
|Birth and death categories|
|Births - Deaths|
|Establishments and disestablishments categories|
|Establishments - Disestablishments|
|Ab urbe condita||2419|
|English Regnal year||17 Cha. 2 – 18 Cha. 2
— to —丙午年十二月初六日
|- Vikram Samvat||1722–1723|
|- Shaka Samvat||1588–1589|
|- Kali Yuga||4767–4768|
|- Ǹrí Ìgbò||666–667|
|Japanese calendar||Kanbun 5
|Juche calendar||N/A (before 1912)|
|Julian calendar||Gregorian minus 10 days|
|Minguo calendar||246 before ROC
|Thai solar calendar||2209|
|Wikimedia Commons has media related to: 1666|
Year 1666 (MDCLXVI) was a common year starting on Friday (link will display the full calendar) of the Gregorian calendar and a common year starting on Monday of the 10-day slower Julian calendar. 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.
- January 17 – The Chair of Saint Peter (Cathedra Petri, designed by Bernini) is set above the altar in St. Peter's Basilica in Rome.
- February 1 – The English royal court returns to London as the Great Plague of London subsides.
- June 4 – Molière's comedy The Misanthrope is premièred at the Théâtre du Palais-Royal in Paris by the King's Players.
- June 11–14 (June 1–4 Julian calendar) – Second Anglo-Dutch War – Four Days' Battle: The Dutch Republic fleet under Michiel de Ruyter defeats that of the Kingdom of England in the North Sea in one of the longest naval engagements in history.
- July – The city of Piteå in Sweden is completely burned by a large fire
- August 4 (July 25 Julian calendar) – Second Anglo-Dutch War – St. James's Day Battle: The English fleet under Prince Rupert of the Rhine and George Monck, 1st Duke of Albemarle, defeats the Dutch off the North Foreland of England.
- August 19–20 (August 9–10 Julian calendar) – 'Holmes's Bonfire': Rear Admiral Robert Holmes leads an English raid on the Dutch island of Terschelling, destroying 150 merchant ships in the Vlie estuary, and pillaging the town of West-Terschelling.
- September 2–5 – Great Fire of London: A large fire breaks out in the City of London in the house of a baker on Pudding Lane near London Bridge. The fire destroys more than 13,000 buildings including Old St Paul's Cathedral but only 6 people are known to have died.
- September 6 – Cestui que Vie Act 1666 passed by the Parliament of England to provide for disposal of the property of missing persons.
- September 16 – Apostasy of Sabbatai Zevi in Istanbul.
- December 22 – The French Academy of Sciences, founded by Louis XIV, first meets.
Date unknown 
- Mughal forces of Emperor Aurangzeb, in alliance with the Portuguese, under Shaista Khan and his son Buzurg Umed Khan expel the Arakans from the Bengal port city of Chittagong, renaming the city as Islamabad.
- Moulay al-Rashid conquers Fes, marking the beginning of Morocco's still-reigning Alaouite dynasty.
- Isaac Newton uses a prism to split sunlight into the component colours of the optical spectrum, assisting understanding of the nature of light. He also develops differential calculus. His discoveries this year lead to it being referred to as his Annus mirabilis.
- Dutch artist Johannes Vermeer paints The Art of Painting, his largest and most complex work.
- Lund University is founded in Lund, Sweden.
- Jean Talon completes a census of New France, the first census in North America.
- The Russian Orthodox Church holds a sobor (church council) which deposes Patriarch Nikon, but accepts his liturgical reforms. Dissenters from his reforms, known as Old Believers, continue to this day.
- This year contains all the Roman numerals used only once in order from the biggest to the smallest value (MDCLXVI = 1666).
- February 1 – Marie Thérèse de Bourbon, Princess of Conti and titular queen of Poland (d.1732)
- February 9 – George Hamilton, 1st Earl of Orkney, British soldier (d. 1737)
- March 15 – George Bähr, German architect (d. 1738)
- May 14 – Victor Amadeus II of Sardinia (d. 1732)
- July 10 – John Ernest Grabe, German-born Anglican theologian (d. 1711)
- July 23 – Thomas Parker, 1st Earl of Macclesfield (d. 1732)
- August 13 – William Wotton, English scholar (d. 1727)
- September 5 – Gottfried Arnold, German church historian (d. 1714)
- September 6 – Tsar Ivan V of Russia (d. 1696)
- December 26 – Guru Gobind Singh, 10th Guru of Sikhism, Founder and Chief General of the Khalsa Army, social reformist, poet, and revolutionary (d. 1708)
- date unknown – Arthur Chichester, 3rd Earl of Donegall (d. 1706)
- January 20 – Anne of Austria, queen of Louis XIII of France and regent (b. 1601)
- January 22 – Shah Jahan, Mughal Emperor of India (b. 1592)
- January 24 – Johann Andreas Herbst, German composer (b. 1588)
- February 24 – Nicholas Lanier, English composer (b. 1588)
- June 16 – Sir Richard Fanshawe, British diplomat and translator (b. 1608)
- June 30 – Alexander Brome, English poet (b. 1620)
- July 5 – Albert VI of Bavaria (b. 1584)
- August 6 – Tjerk Hiddes de Vries, Frisian naval hero and commander (of wounds received at St. James's Day Battle) (b. 1622)
- August 15 – Johann Adam Schall von Bell, German Jesuit missionary (b. 1591)
- August 26 – Frans Hals, Dutch painter (b. 1580)
- October 29 – Edmund Calamy the Elder, English Presbyterian leader (b. 1600)
- October 29 – James Shirley, English dramatist (b. 1596)
- December 9 – Giovanni Francesco Barbieri (Guercino), Italian painter (b. 1591)
- date unknown
- "Cathedra Petri – Altar of the Chair of St. Peter". St Peters Basilica. Retrieved 2013-03-01.
- Palmer, Alan; Veronica (1992). The Chronology of British History. London: Century Ltd. pp. 190–191. ISBN 0-7126-5616-2.
- Frame, Donald M. The Misanthrope and Other Plays by Molière.
- Penguin Pocket On This Day. Penguin Reference Library. 2006. ISBN 0-14-102715-0.