1811

1811 in various calendars
Gregorian calendar	1811; MDCCCXI
Ab urbe condita	2564
Armenian calendar	1260; ԹՎ ՌՄԿ
Assyrian calendar	6561
Balinese saka calendar	1732–1733
Bengali calendar	1218
Berber calendar	2761
British Regnal year	51 Geo. 3 – 52 Geo. 3
Buddhist calendar	2355
Burmese calendar	1173
Byzantine calendar	7319–7320
Chinese calendar	庚午年 (Metal Horse); 4508 or 4301; — to —; 辛未年 (Metal Goat); 4509 or 4302
Coptic calendar	1527–1528
Discordian calendar	2977
Ethiopian calendar	1803–1804
Hebrew calendar	5571–5572
Hindu calendars
- Vikram Samvat	1867–1868
- Shaka Samvat	1732–1733
- Kali Yuga	4911–4912
Holocene calendar	11811
Igbo calendar	811–812
Iranian calendar	1189–1190
Islamic calendar	1225–1226
Japanese calendar	Bunka 8; (文化８年)
Javanese calendar	1737–1738
Julian calendar	Gregorian minus 12 days
Korean calendar	4144
Minguo calendar	101 before ROC; 民前101年
Nanakshahi calendar	343
Thai solar calendar	2353–2354
Tibetan calendar	阳金马年; (male Iron-Horse); 1937 or 1556 or 784; — to —; 阴金羊年; (female Iron-Goat); 1938 or 1557 or 785

Millennium:	2nd millennium
Centuries:	18th century; 19th century ; 20th century;
Decades:	1790s; 1800s; 1810s ; 1820s; 1830s;
Years:	1808; 1809; 1810; 1811 ; 1812; 1813; 1814;

Year 1811 (MDCCCXI) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Sunday of the 12-day slower Julian calendar).

Events of 1811

January 3 – An unsuccessful slave revolt is led by Charles Deslandes in St. Charles and St. James, Louisiana.
January 22 – The Casas Revolt begins in San Antonio, Texas.
February 5 – British Regency: George, Prince of Wales becomes Prince Regent because of the perceived insanity of his father, King George III of the United Kingdom.
March 1 – Citadel Massacre: Egyptian ruler Mohammed Ali kills the last Mamluk leaders.
March 13 – Battle of Lissa (1811): The British fleet defeats the French.
March 22 – The Commissioners' Plan of 1811 for Manhattan is presented.
March 25 – The Great Comet of 1811 is discovered by Honoré Flaugergues.
March 27 – Battle of Anholt: The British navy defeats Denmark.

July 5 – Venezuela declares its independence from Spain.
July 11 – Italian scientist Amedeo Avogadro publishes his memoire about the molecular content of gases.
August 3 – First ascent of Jungfrau, third highest summit in the Bernese Alps,
September – Nathan of Breslov leads the first annual Rosh Hashana kibbutz (pilgrimage) of Breslov Hasidim to the grave of Rabbi Nachman of Breslov in Uman, Ukraine.

October 11 – Inventor John Stevens' boat, the Juliana, begins operation as the first steam-powered ferry (service between New York, New York, and Hoboken, New Jersey).
November – Luddite uprisings begin in northern England and the Midlands.
November 6 – Battle of Tippecanoe: American troops led by William Henry Harrison defeat the Native American chief Tecumseh.
November 17 – José Miguel Carrera, Chilean founding father, is sworn in as President of the executive Junta of the government of Chile.
December 16 – The New Madrid earthquake in Mississippi Valley near New Madrid reverses the course of the river for a while. Other earthquakes along the fault occur on January 23, 1812 and February 7, 1812.

July 18 – William Makepeace Thackeray, British novelist (d. 1863)
August 31 – Theophile Gautier, French writer (d. 1872)
September 19 – Orson Pratt, American religious leader (d. 1881)
October 22 – Franz Liszt, Hungarian composer and pianist (d. 1886)
October 25 – Évariste Galois, French mathematician (d. 1832)
October 27 – Stevens Thomson Mason, first governor of Michigan (d. 1843)
November 21
- Zeng Guofan, Chinese official and military leader (d. 1872)
- Ludwig Preiss, Botanical collector (d. 1883)
November 24 – Ulrich Ochsenbein, Swiss Federal Councilor (d. 1890)
December 21 – Archibald Campbell Tait, Archbishop of Canterbury (d. 1882)
date unknown
- Mohammad Afzal Khan, Emir of Kabul, Emir of Kandahar (d. 1867)

July 30 – Miguel Hidalgo y Costilla, Mexican revolutionary (b. 1753)
August – William Williams, signer of the Declaration of Independence (b. 1731)
August 20 – Louis Antoine de Bougainville, French navigator and military commander (b. 1729)
September – Ulrich Jasper Seetzen, explorer (b. 1767)
September 8 – Peter Simon Pallas, German zoologist (b. 1741)
October 11 – Johann Conrad Ammann, Swiss physician and naturalist (b. 1724)
November 21 – Heinrich von Kleist, German writer (suicide) (b. 1777)
November 27 – Andrew Meikle, Scottish engineer (b. 1719)