1811 was a common year starting on Tuesday (see link for calendar).
| Gregorian calendar | 1811 MDCCCXI |
| Ab urbe condita | 2564 |
| Armenian calendar | 1260 ԹՎ ՌՄԿ |
| Assyrian calendar | 6561 |
| Balinese saka calendar | 1732–1733 |
| Bengali calendar | 1217–1218 |
| 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 | ལྕགས་ཕོ་རྟ་ལོ་ (male Iron-Horse) 1937 or 1556 or 784 — to — ལྕགས་མོ་ལུག་ལོ་ (female Iron-Sheep) 1938 or 1557 or 785 |
Wikimedia Commons has media related to 1811.
| Gregorian calendar | 1811 MDCCCXI |
| Ab urbe condita | 2564 |
| Armenian calendar | 1260 ԹՎ ՌՄԿ |
| Assyrian calendar | 6561 |
| Balinese saka calendar | 1732–1733 |
| Bengali calendar | 1217–1218 |
| 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 | ལྕགས་ཕོ་རྟ་ལོ་ (male Iron-Horse) 1937 or 1556 or 784 — to — ལྕགས་མོ་ལུག་ལོ་ (female Iron-Sheep) 1938 or 1557 or 785 |
Events
- January 8 - Unsuccessful slave revolt led by Charles Deslandes in St. Charles and St. James, Louisiana.
- February 5 - George, Prince of Wales becomes Regent because of the perceived insanity of his father, King George III of the United Kingdom.He is known as the Prince Regent. This is the beginning of the period known as the English Regency.
- March 1 - Egyptian ruler Mohammed Ali kills the last Mamluk leaders in the Citadel Massacre.
- March 13 - Battle of Lissa (1811) - British fleet defeats the French one.
- March 25 - The Great Comet of 1811 is discovered by Honoré Flaugergues.
- April 5- April 6 - Revolutionary riots in Buenos Aires.
- May 14 - Paraguay declares independence from Spain.
- May 16 - Battle of Albuhera.
- July 5 - Venezuela declares its independence from Spain.
- July 11 - Italian scientist Amedeo Avogadro publishes his memoire about molecular content of gases.
- September - First annual Rosh Hashana kibbutz (pilgrimage) of Breslov Hasidim to the grave of Rabbi Nachman of Breslov in Uman, Ukraine, led by Nathan of Breslov.
- 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 Midlands.
- November 16 - Earthquake in Mississippi Valley near New Madrid reverses the course of the river for a while.
- London and Westminster Chartered Gas Society founded in London.
- Bolivia declares indepencence.
- Uruguay revolts against Spain.
- Battle of Tippecanoe.
Ongoing events
Births
- January 9 - Gilbert Abbott à Beckett, English writer (d. 1856)
- January 17 - Joshua Abraham Norton, self-declared Emperor Norton I of the United States (d. 1880)
- February 3 - Horace Greeley, American journalist, editor, and publisher (d. 1872)
- February 6 - Henry George Liddell, English clergyman (d. 1898)
- March 20 - Napoleon II of France (d. 1832)
- March 30 - Robert Bunsen, German chemist and inventor (d. 1899)
- June 14 - Harriet Beecher Stowe, American author (d. 1896)
- 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)
- November 24 - Ulrich Ochsenbein, Swiss Federal Councilor (d. 1890)
- December 21 - Archibald Campbell Tait, Archbishop of Canterbury (d. 1882)
Deaths
- January 10 - Marie-Joseph Chénier, French poet (b. 1764)
- May 28 - Henry Dundas, 1st Viscount Melville, British minister (b. 1742)
- August 20 - Louis Antoine de Bougainville, French navigator and military commander (b. 1729)
- September 8 - Peter Simon Pallas, German zoologist (b. 1741)
- October 11 - Johann Conrad Ammann, Swiss physician and naturalist (b. 1724)
- November 18 - Adam Weishaupt, German founder of the Illuminati (b. 1748)
- November 21 - Heinrich von Kleist, German writer (suicide) (b. 1777)
- November 27 - Andrew Meikle, English engineer (b. 1719)
Wikimedia Commons has media related to 1811.