|Centuries:||17th century – 18th century – 19th century|
|Decades:||1750s 1760s 1770s – 1780s – 1790s 1800s 1810s|
|Years:||1783 1784 1785 – 1786 – 1787 1788 1789|
|1786 by topic:|
|Arts and Sciences|
|Archaeology – Architecture – Art – Literature (Poetry) – Music – Science|
|Canada –Denmark – France – Great Britain – Ireland – Norway – Russia – Scotland –Sweden – United States|
|Lists of leaders|
|Colonial governors – State leaders|
|Birth and death categories|
|Births – Deaths|
|Establishments and disestablishments categories|
|Establishments – Disestablishments|
|Ab urbe condita||2539|
|British Regnal year||26 Geo. 3 – 27 Geo. 3|
|Chinese calendar||乙巳年 (Wood Snake)
4482 or 4422
— to —
丙午年 (Fire Horse)
4483 or 4423
|- Vikram Samvat||1842–1843|
|- Shaka Samvat||1708–1709|
|- Kali Yuga||4887–4888|
|Japanese calendar||Tenmei 6
|Julian calendar||Gregorian minus 11 days|
|Minguo calendar||126 before ROC
|Thai solar calendar||2328–2329|
|Wikimedia Commons has media related to 1786.|
1786 (MDCCLXXXVI) was a common year starting on Sunday (dominical letter A) of the Gregorian calendar and a common year starting on Thursday (dominical letter D) of the Julian calendar, the 1786th year of the Common Era (CE) and Anno Domini (AD) designations, the 786th year of the 2nd millennium, the 86th year of the 18th century, and the 7th year of the 1780s decade. As of the start of 1786, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1918.
- January 3 – The third Treaty of Hopewell was signed between the United States of America and the Choctaw.
- January 6 – The outward bound East Indiaman Halsewell was wrecked on the south coast of England in a storm with only 74 of more than 240 on board surviving.
- February 2 – In a speech before The Asiatic Society in Calcutta, Sir William Jones noted the formal resemblances between Latin, Greek, and Sanskrit, laying the foundation for comparative linguistics and Indo-European studies.
- May 1 – Mozart's opera The Marriage of Figaro premiered in Vienna.
- May 21 – The trial in the Affair of the Diamond Necklace ended in Paris.
- June 10 – An earthquake-caused landslide dam on the Dadu River gave way, killing 100,000 in the Sichuan province of China.
- June 25 – Gavriil Pribylov discovered St. George Island of the Pribilof Islands in the Bering Sea.
- July 14 – Convention of London between the Kingdom of Great Britain and the Kingdom of Spain: British settlements on the Mosquito Coast of Central America were to be evacuated; Spain expanded the territory available to the British in Belize on the Yucatán Peninsula for cutting mahogany.
- July 31 – "Kilmarnock volume" of Robert Burns' Poems, Chiefly in the Scottish Dialect published in Scotland.
- August 1 – Caroline Herschel discovered a comet (the first discovered by a woman).
- August 8 – Mont Blanc was climbed for the first time by Dr. Michel-Gabriel Paccard and Jacques Balmat.
- August 11 – Captain Francis Light acquired the island of Penang from the Sultan of Kedah on behalf of the British East India Company, renaming it Prince of Wales Island in honour of the heir to the British throne, the first colony of the British Empire in Southeast Asia.
- August 17 : The paternal nephew of Frederick the Great, Frederick William, became King of Prussia, as Frederick William II.
- August 18 : The Kingdom of Denmark–Norway chartered six settlements in Iceland to trade with it, thus ending the Danish–Icelandic Trade Monopoly and founding Reykjavík.
- August 29 – Shays' Rebellion began in Massachusetts.
- September–December – Goethe undertook his Italian Journey (published in 1817).
- September 2 – A hurricane struck Barbados.
- September 11–14 – Annapolis Convention was held, resulting in scheduling of the Philadelphia Convention.
- September 26 – Eden Agreement: Commercial treaty was signed between the Kingdoms of Great Britain and France.
- November 7 – The oldest musical organization in the United States, the Stoughton Musical Society, was founded.
- November 30 – Peter Leopold Joseph of Habsburg-Lorraine, Grand Duke of Tuscany, promulgated a penal reform making his country the first state to abolish the death penalty. November 30 is therefore commemorated by 300 cities around the world as Cities for Life Day.
- December 4 – Mission Santa Barbara was founded by Padre Fermín Lasuén as the tenth of the Spanish missions in California.
- December 20 – Robert Burns' "Address to a Haggis" first published, in Edinburgh.
- The town of Martinsborough, North Carolina, named for Royal Governor Josiah Martin in 1771, was renamed "Greenesville" in honor of United States General Nathanael Greene by the North Carolina General Assembly; the name "Greenesville" was later shortened to become Greenville.
- The last reliably recorded wolf in Ireland was hunted down and killed near Mount Leinster, County Carlow, for killing sheep.
- January 8 – Nicholas Biddle, President of the Second Bank of the United States (d. 1844)
- January 12 – Sir Robert Inglis, Bt, English politician (d. 1855)
- January 23 – Auguste de Montferrand, French architect (d. 1858)
- February 16 – Maria Pavlovna of Russia, Grand duchess of Saxe-Weimar Eisenach (d. 1859)
- February 24 – Martin W. Bates, U.S. Senator from Delaware (d. 1869)
- February 26 – François Arago, French astronomer, physicist and politician (d. 1853)
- February 24 – Wilhelm Grimm, German philologist and folklorist (d. 1859)
- March 22 – Joachim Lelewel, Polish historian (d. 1861)
- March 25 – Giovanni Battista Amici Italian astronomer, microscopist, and botanist (d. 1863)
- April 16 – John Franklin, British naval officer and explorer (d. 1847)
- May 12 – Jean-François Barrière, French historian (d. 1868)
- May 29 – Alexander Bryan Johnson, American philosopher (d. 1867)
- June 13 – Winfield Scott, American general and Presidential candidate (d. 1866)
- August 17
- August 25 – King Ludwig I of Bavaria (d. 1868)
- August 31 – Michel Eugène Chevreul, French chemist (d. 1889)
- September 10 – William Mason, American politician (d. 1860)
- September 11 – Friedrich Kuhlau, German composer (d. 1832)
- September 18
- September 24 – Charles Bianconi, Italian-Irish entrepreneur (d. 1875)
- September 29 – Guadalupe Victoria, 1st President of Mexico (d. 1843)
- November 18
- December 12 – William L. Marcy, American statesman (d. 1857)
- Caroline Cornwallis, English writer (d. 1858)
- Kim Jeong-hui, Korean epigrapher (d. 1856)
- probable – Moshoeshoe I of Lesotho (d. 1870)
- January 4 – Moses Mendelssohn, Jewish philosopher (b. 1729)
- January 7 – Jean-Étienne Guettard, French physician and scientist (b. 1715)
- January 14 – Meshech Weare, Governor of New Hampshire (b. 1713)
- February 28 – John Gwynn, English architect and engineer (b. 1713)
- March 11 – Charles Humphreys, American delegate to the Continental Congress (b. 1714)
- April 10 – John Byron, British naval officer (b. 1723)
- May 15 – Eva Ekeblad, Swedish scientist & agronomist, first female member of the Royal Swedish Academy of Sciences (b.1724)
- May 19 – John Stanley, English composer (b. 1712)
- May 21 – Carl Wilhelm Scheele, Swedish chemist (b. 1742)
- May 25 – Pedro III of Portugal, consort of Queen Maria I of Portugal (b. 1717)
- June 19 – Nathanael Greene, major general in the Continental Army, 3rd Quartermaster General (b. 1742)
- August 17 – King Frederick II of Prussia ("Frederick the Great") (b. 1712)
- September 5 – Jonas Hanway, English merchant, traveler, and philanthropist (b. 1712)
- October 2 – Augustus Keppel, 1st Viscount Keppel, British admiral (b. 1725)
- October 17 – Johann Ludwig Aberli, Swiss artist (b. 1723)
- October 20 – Humphrey Sturt, British architect (b. 1725)
- November 30 – Bernardo de Gálvez, Spanish military leader who aided the United States in its quest for independence in the American Revolutionary War (b. 1746)
- December 26 – Gasparo Gozzi, Italian critic and dramatist (b. 1713)
- "Loss of the Halsewell East-Indiaman". Remarkable Shipwrecks; Or, A Collection of Interesting Accounts of Naval Disasters: With Many Particulars of the Extraordinary Adventures and Sufferings of the Crews of Vessels Wrecked at Sea, and of Their Treatment on Distant Shores. Together with an Account of the Deliverance of Survivors. Andrus and Starr. 1813. Retrieved 2013-02-02.
- Williams, Hywel (2005). Cassell's Chronology of World History. London: Weidenfeld & Nicolson. p. 339. ISBN 0-304-35730-8.
- Palmer, Alan; Veronica (1992). The Chronology of British History. London: Century Ltd. pp. 230–231. ISBN 0-7126-5616-2.
- Hickey, Kieran R. (2000). "A geographical perspective on the decline and extermination of the Irish wolf canis lupus" (PDF). Irish Geography. 33: 185–98. Retrieved 2011-02-25.