1810 (MDCCCX) was a common year starting on Monday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1810th year of the Common Era (CE) and Anno Domini (AD) designations, the 810th year of the 2nd millennium, the 10th year of the 19th century, and the 1st year of the 1810s decade. As of the start of 1810, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.
|Ab urbe condita||2563|
|Balinese saka calendar||1731–1732|
|British Regnal year||50 Geo. 3 – 51 Geo. 3|
|Chinese calendar||己巳年 (Earth Snake)|
4506 or 4446
— to —
庚午年 (Metal Horse)
4507 or 4447
|- Vikram Samvat||1866–1867|
|- Shaka Samvat||1731–1732|
|- Kali Yuga||4910–4911|
|Japanese calendar||Bunka 7|
|Julian calendar||Gregorian minus 12 days|
|Minguo calendar||102 before ROC|
|Thai solar calendar||2352–2353|
1936 or 1555 or 783
— to —
1937 or 1556 or 784
|Wikimedia Commons has media related to 1810.|
- January 1 – Major-General Lachlan Macquarie officially becomes Governor of New South Wales.
- January 4 – Australian seal hunter Frederick Hasselborough discovers Campbell Island, in the Subantarctic.
- January 12 – The marriage of Napoleon and Joséphine is annulled.
- February 20 – Tyrolean rebel leader Andreas Hofer is executed.
- March 4 – Peninsular War: The French Army, under the command of André Masséna, retreats from Portugal.
- March 11 – Napoleon marries Marie-Louise of Austria.
- April 19 – Venezuela achieves home rule: Vicente Emparán, Governor of the Captaincy General of Venezuela, is removed by the people of Caracas, and Supreme Junta is installed. Venezuela is the first South American state to proclaim independence from Spain.
- April 27 – Beethoven composes his famous piano piece, Für Elise.
- May 1 – Macon's Bill Number 2 becomes law in the United States, intending to motivate Britain and France to stop seizing American vessels during the Napoleonic Wars.
- May 3 – Lord Byron swims across the Hellespont in Turkey.
- May 10 – Rev. Henry Duncan opens the world's first commercial savings bank, in Ruthwell, Scotland.
- May 16 – Johann Wolfgang von Goethe publishes his book Zu Farbenlehre (Theory of Colours). 
- May 18–25 – May Revolution: Armed citizens of Buenos Aires expel the Viceroy and establish a provincial government for Argentina (the Primera Junta).
- June 4 – The Society in Dedham for Apprehending Horse Thieves is founded in Dedham, Massachusetts.
- June 23 – John Jacob Astor forms the Pacific Fur Company.
- June – Nicolas Appert publishes L'art de conserver pendant plusieurs années toutes les substances animales ou végétales, the first description of modern food preservation using airtight containers.
- April – Summer – The Kingdom of Hawaii is unified.
- July 9
- July 11 – Frederick Hasselborough discovers Macquarie Island, in the subantarctic.
- July 20 – Patria Boba: A junta of seven patriots, led by José Acevedo y Gómez, assemble in Bogotá in the Viceroyalty of New Granada (modern-day Colombia), to declare its independence from the Spanish Empire.
- August 2 – In Quito, Ecuador, 200 citizens are slaughtered in the Royal barracks and the surrounding streets, by royalist troops.
- August 6 – The city of Santa Cruz de Mompox, in modern-day Colombia, declares independence from the Spanish Empire.
- August 20–27 – Battle of Grand Port: The French force the British Royal Navy fleet, attempting to blockade a harbour on Isle de France (Mauritius), to surrender.
- August 21 – Jean Baptiste Bernadotte, Marshal of France, is elected Crown Prince of Sweden, by the Swedish Riksdag of the Estates.
- September 8 – The Tonquin sets sail from New York Harbor, with 33 employees of John Jacob Astor's newly created Pacific Fur Company on board. After a six-month journey around the tip of South America, the ship arrives at the mouth of the Columbia River, and Astor's men establish the fur-trading town of Astoria.
- September 16 – Grito de Dolores: Miguel Hidalgo, a Catholic priest from Guanajuato, incites the revolt that becomes the Mexican War of Independence.
- September 18 – Chile forms its First National Junta, which is the country's first step towards its independence.
- September 23 – The Republic of West Florida declares independence from Spain.
- September 26 – A new Act of Succession is adopted by the Riksdag of the Estates, and Jean Baptiste Bernadotte becomes heir to the Swedish throne.
- October – King George III of the United Kingdom is recognized as insane.
- October 12 – First Oktoberfest: Bavarian royalty invites the citizens of Munich to join the celebration of the marriage of Crown Prince Ludwig of Bavaria, to Princess Therese of Saxe-Hildburghausen.
- October 27 – The United States annexes the Republic of West Florida.
- November 2 – A peace treaty in Haiti confirms its division between the northern State of Haiti, ruled autocratically by the gen de couleur Henri Christophe, and the southern Republic, ruled by mulatto Alexandre Pétion. Steeve Coupeau, The History of Haiti (Greenwood, 2008) p49
- November 17 – Anglo-Swedish War (1810–12): Sweden declares war on the United Kingdom.
- November 23 – English actress Sarah Booth debuts at the Theatre Royal, Covent Garden in London.
- November 29–December 3 – Invasion of Isle de France: British forces force the French to surrender Isle de France (Mauritius).
- Amadou Lobbo initiates his jihad, in present-day Mali.
- Ching Shih and Cheung Po Tsai surrender their pirate fleet to the Chinese government.
- The first steamboat sails on the Ohio River.
- The General Union of Spinners organizes a strike action, to raise wages in the smaller UK cotton centres to the Manchester level.
- The Saint Petersburg main military engineering school becomes the first engineering higher learning institution in the Russian Empire, after the addition of officers' classes, and the application of a five-year term of teaching.
- Friedrich Krupp establishes a steel foundry in Essen.
- Rocky Point Manor is built in Harrodsburg, Kentucky.
- Moose become extinct in the Caucasus.
- 18,000 Angolans are sold at Rio de Janeiro, Brazil.
- Palm oil sales from West Africa to Britain reach 1,000 tons.
- 4,500 chests of opium are sold in China.
- Sake Dean Mahomed opens the Hindoostanee Coffee House, the first Indian restaurant in London.
- January 3 – Antoine Thomson d'Abbadie, Irish-French geographer (d. 1897)
- January 13 – Ernestine Rose, Polish-born feminist (d. 1892)
- January 29 – Ernst Kummer, German mathematician (d. 1893)
- February 5 – Ole Bull, Norwegian violinist (d. 1880)
- February 8 – Eliphas Levi, French writer (d. 1875)
- March 1 – Frédéric Chopin, Polish composer, pianist (d. 1849)
- March 2 – Pope Leo XIII (b. Vincenzo Gioacchino Raffaele Luigi Pecci) (d. 1903)
- March 10 – Samuel Ferguson, Northern Irish poet, artist (d. 1886)
- March 28 – Alexandre Herculano, Portuguese writer and historian (d. 1877)
- April 8 – Hégésippe Moreau, French writer and poet (d. 1838)
- May 2 – Hans Christian Lumbye, Danish composer (d. 1874)
- May 23 – Margaret Fuller, American journalist, literary critic and feminist (drowning) (d.1850)
- May 24 – Abraham Geiger, German rabbi, founder of European Reform Judaism (d. 1874)
- May 31 – Horatio Seymour, 18th Governor of New York, 1868 Democratic Party Presidential Nominee (d. 1886)
- June 8 – Robert Schumann, German composer, pianist (d. 1856)
- June 9 – Carl Otto Nicolai, German composer, conductor (d. 1849)
- June 14 – Ward Hunt, Associate Justice of the Supreme Court of the United States (d. 1886)
- July 5 – P. T. Barnum, American showman (d. 1891)
- July 20 – Leonhard Graf von Blumenthal, Prussian field marshal (d. 1900)
- July 21 – Henri Victor Regnault, French chemist, physicist (d. 1878)
- August 4 – Maurice de Guérin, French poet (d. 1839)
- August 10 – Camillo Benso, Count of Cavour, 1st Prime Minister of Italy (d. 1861)
- August 24 – Theodore Parker, American preacher, Transcendentalist, and abolitionist (d. 1860)
- August 29 – Juan Bautista Alberdi, Argentinian politician, writer and Constitution main promoter (d. 1884)
- September 2 – William Seymour Tyler, American educator, historian (d. 1897)
- September 11 – James Pollock, American politician (d. 1890)
- September 29 – Elizabeth Gaskell, British novelist (d. 1865)
- October 4 – Eliza McCardle Johnson, First Lady of the United States (d. 1876)
- October 8 – James W. Marshall, American contractor, builder of Sutter's Mill (d. 1885)
- November 2 – Andrew A. Humphreys, American general, civil engineer (d. 1883)
- November 3 – Yisroel Salanter, father of the Musar movement in Orthodox Judaism (d. 1883)
- November 26 – William Armstrong, 1st Baron Armstrong, English engineer, inventor of the Hydraulic accumulator (d. 1900)
- December 7 – Theodor Schwann, German physiologist (d. 1882)
- December 11 – Alfred de Musset, French poet (d. 1857)
- December 24 – Wilhelm Marstrand, Danish painter (d. 1873)
- January 15 – Yekaterina Romanovna Vorontsova-Dashkova, Russian princess, courtier and patron of the arts and sciences, first woman to head a scientific academy (b. 1743)
- January 20 – Benjamin Chew, Chief Justice of colonial Pennsylvania (b. 1722)
- January 23 – Johann Wilhelm Ritter, German chemist, physicist (b. 1776)
- February 20 – Andreas Hofer, Tyrolean national hero (executed) (b. 1767)
- February 24 – Henry Cavendish, British scientist (b. 1731)
- March 6 – William Washington, United States soldier (b. 1752)
- March 7 – Cuthbert Collingwood, 1st Baron Collingwood, British admiral (b. 1750)
- March 12 – Jean-François-Auguste Moulin, member of the French Directory (b. 1752)
- April 25 – Jacob Broom, American businessman, politician (b. 1752)
- April 26 – John Metcalf, English roadbuilder (b. 1717)
- May 9 – Benjamin Lincoln, major general in the Continental Army during the American Revolutionary War (b. 1733)
- May 15 – Francis Hews, Baptist preacher in Bedfordshire, England.
- May 21 – Chevalier d'Eon, French-born diplomat, spy, soldier and transvestite (b. 1728)
- May 26 – Catharina Heybeek, Dutch journalist, feminist and editor (d. 1764)
- June 7 – Luigi Schiavonetti, Italian engraver (b. 1765)
- June 26 – Joseph-Michel Montgolfier, French inventor (b. 1740)
- July 19 – Louise of Mecklenburg-Strelitz, Queen of Prussia (b. 1776)
- August 12 – Étienne Louis Geoffroy, French pharmacist, entomologist (b. 1725)
- August 26 – Santiago de Liniers, 1st Count of Buenos Aires, French officer in Spanish colonial military service (executed) (b. 1753)
- September 17 – Ulla von Höpken, Swedish courtier, influential socialite (b. 1749)
- October 15 – Alfred Moore, American judge (b. 1755)
- November 2 – Princess Amelia of the United Kingdom, Member of the British Royal Family (b. 1783)
- November 11
- December 2 – Philipp Otto Runge, German painter (b. 1777)
- December 5 – Kumara Swamy Desikar, Indian philosopher (b. 1711)
- September 13 – William Cushing, Associate Justice of the Supreme Court of the United States (b. 1732)
- Mills, William James (2003). Exploring polar frontiers: a historical encyclopedia. Santa Barbara: ABC-CLIO.
- Penguin Pocket On This Day. Penguin Reference Library. 2006. ISBN 0-14-102715-0.
- "Chronology of Scottish History". A Timeline of Scottish History. Rampant Scotland. Retrieved March 10, 2014.
- Götz Hoeppe, Why the Sky is Blue: Discovering the Color of Life (Princeton University Press, 2007) p126
- George Hewitt, The Abkhazians: A Handbook (Routledge, 2013) p74
- Rubin, Jeff (2005). Antarctica. Lonely Planet. p. 170. ISBN 1-74059-094-5. Retrieved June 30, 2010.
- Scott, Keith (1993). The Australian Geographic book of Antarctica. Terrey Hills, NSW: Australian Geographic. p. 14. ISBN 1-86276-010-1.
- "Icons, a portrait of England 1800-1820". Archived from the original on October 17, 2007. Retrieved September 11, 2007.
- A baptismal record gives February 22; see Frédéric Chopin for details.