January 14 – Denmark cedes Norway into personal union with Sweden in exchange for west Pomerania, as part of the Treaty of Kiel. Sweden never again takes part in war.
January 29 – Battle of Brienne: Emperor Napoleon I of France is victorious against von Blücher.
January 31 – Gervasio Antonio de Posadas becomes Supreme Director of Argentina.
February – George Hamilton-Gordon, 4th Earl of Aberdeen, represents Britain at the Congress of Chatillon.
February 1 – Lord Byron's semi-autobiographical tale in verse The Corsair is published by John Murray in London and sells 10,000 copies on this day.
February 11 – Norway's independence is proclaimed, marking the ultimate end of the Kalmar Union.
February 12 – A fire destroys the Custom House, London.
February 14 – Battle of Vauchamps: Napoleon I of France is victorious against von Blücher.
February 18 – Battle of Montereau: Napoleon is victorious against Austrian forces.
February 21 – Great Stock Exchange Fraud in London.
March 7 – Battle of Craonne: Napoleon is victorious against von Blücher.
March 8 – Napoleonic Wars: A night attack by the British under Sir Thomas Graham on the French fortress of Bergen op Zoom ends in failure.
March 9 – American naval schooner USS Enterprise reaches Wilmington, North Carolina, returning from participating in the War of 1812 against the United Kingdom in the Caribbean.
March 10 – Battle of Laon: von Blücher defeats Napoleon.
March 12 – Louis Antoine, Duke of Angoulême enters Bordeaux, marking the restoration of the House of Bourbon.
March 25 – De Nederlandsche Bank is established.
March 27 – War of 1812 – Battle of Horseshoe Bend: In northern Alabama, United States forces under General Andrew Jackson defeat the Creek Indians.
March 30 – Napoleonic Wars: Battle of Paris.
March 31 – Anti-Napoleonic troops occupy Paris.
April 6 – Bourbon Restoration: Louis XVIII is invited to occupy the restored French throne.
April 10 – The Duke of Wellington wins the Battle of Toulouse.
April 11 – Napoleon abdicates unconditionally as Emperor of the French.
April 12 – The Royal Norwegian Navy is re-established.
April 18/19 – Genoa surrenders to the British Royal Navy.
April 28 – Ligurian Republic revived.
May 3 – The Duke of Provence, the future Louis XVIII of France, returns to Paris.
May 4 – Ferdinand VII of Spain abolishes the Spanish Constitution of 1812, returning the country to absolute monarchy.
May 5 – British-American War (War of 1812): British forces attack Fort Ontario at Oswego, New York.
The Constitution of Norway is signed and the Danish Crown Prince Christian Frederik is elected King of Norway by the Norwegian Constituent Assembly.
The occupation of Monaco changes from French to Austrian hands.
May 30 – The First Treaty of Paris is signed returning France's borders to their 1792 extent. Napoleon is exiled to Elba on the same day.
July 5 – War of 1812 – Battle of Chippawa: American Major General Jacob Brown defeats British General Phineas Riall at Chippawa, Ontario.
July 7 – Walter Scott's Waverley, his first prose fiction and one of the first significant historical novels in English, is published anonymously by Archibald Constable in Edinburgh, selling out in two days.
July 13 – The Carabinieri, the national military police of Italy, is established by Victor Emmanuel as the police force of the Kingdom of Sardinia.
July 24 – War of 1812: General Phineas Riall advances toward Niagara Falls, Ontario to halt Jacob Brown's American invaders.
George Stephenson tests his first locomotive Blücher successfully in England.
War of 1812 – Battle of Lundy's Lane: Reinforcements arrive near Niagara Falls, Ontario for General Riall's British and Canadian force, and a bloody, all-night battle with Jacob Brown's Americans commences at 1800 hours; Americans retreat to Fort Erie.
July 28 – The revived Ligurian Republic is dissolved.
August 7 – Pope Pius VII decrees the bull Sollicitudo omnium ecclesiarum reestablishing the Society of Jesus (Jesuits) all over the world, after having approved their survival and existence in Russia.
August 12 – In England, the last hanging under the Black Act is carried out, of William Potter for cutting down an orchard (although the judge petitions for reprieve).
August 13 – The Anglo-Dutch Treaty of 1814 is signed in London, returning most possessions of the Dutch Empire acquired by the United Kingdom since 1803 to the Netherlands, although Britain retains the Cape of Good Hope and the South American settlements of Demerara, Essequibo and Berbice (later consolidated as British Guiana). In addition, the British cede the island of Banca off the island of Sumatra in exchange for the settlement of Cochin in India.
August 24 – War of 1812: Burning of Washington – British troops, after defeating American forces, at the Battle of Bladensburg, occupy Washington, D.C., setting numerous buildings on fire, including the Capitol and Presidential Mansion.
August 28 – Alexandria, Virginia, offers surrender to the British fleet without a fight.
September 11 – War of 1812 – Battle of Lake Champlain: An American squadron under Thomas Macdonough defeats the British squadron, ultimately forcing the invading army to retreat back into Canada.
September 13 – War of 1812: The British bombard Fort McHenry at Baltimore. The British failure at the Battle of Baltimore is a turning point in the war, and the American defense of the fort inspires Francis Scott Key to compose the poem later set to music as The Star-Spangled Banner.
October 17 – London Beer Flood: A large vat full of porter (beer) owned by Meux's Brewery of London bursts, demolishing buildings and killing nine.
November 4 – King Charles XIII of Sweden becomes King of Norway, as Charles II .
November 7 – War of 1812: Andrew Jackson seizes Pensacola, Florida.
November – Congress of Vienna: The settling of the many issues arising from the French Revolutionary Wars, the Napoleonic Wars, and the dissolution of the Holy Roman Empire.
December 15 – The Hartford Convention is convened by members of the American Federalist Party.
December 24 – War of 1812: The Treaty of Ghent is signed, formally ending the war.
December 25 – Samuel Marsden of the Church Missionary Society preaches the first sermon in New Zealand at Oihi.
Missionaries attempt to write down the Māori language.
The world's first complex machine mass-produced from interchangeable parts, Eli Terry's wooden pillar-and-scroll clock, comes off the production line in Plymouth, Connecticut.
January 1 – Hong Xiuquan, Chinese rebel (d. 1864)
January 27 – Eugène Viollet-le-Duc, French architect (d. 1879)
February 9 – Samuel J. Tilden, 25th Governor of New York, 1876 Democratic Party Presidential Nominee (d. 1886)
February 18 – Samuel Fenton Cary, American politician and temperance activist (d. 1900)
March 9 – Taras Shevchenko, Ukrainian poet (d. 1861)
April 3 – Lorenzo Snow, fifth president of The Church of Jesus Christ of Latter-day Saints (d. 1901)
April 21 – Angela Burdett-Coutts, 1st Baroness Burdett-Coutts, English philanthropist (d. 1906)
May 7 – Henriette Hansen, Norwegian ballerina, singer and actor (d. 1892)
May 12 – Adolf von Henselt, German composer (d. 1889)
Wilhelm Engerth, Austrian architect and engineer (d. 1884)
Heinrich Geißler, German physicist (d. 1879)
May 30 – Mikhail Bakunin, Russian anarchist (d. 1876)
July 3 – Ferdinand Didrichsen, Danish botanist and physicist (d. 1887)
July 19 – Samuel Colt, American gun maker (d. 1862)
August 8 – Esther Morris, American suffragist and judge (d. 1902)
August 10 – Henri Nestlé, German-born Swiss chocolate magnate (d. 1890)
August 13 – Anders Jonas Ångström, Swedish physicist (d. 1874)
August 23 – James Roosevelt Bayley, first Roman Catholic Bishop of Newark, New Jersey, and eighth Archbishop of Baltimore (d. 1877)
August 28 – Sheridan Le Fanu, Irish writer (d. 1873)
September 2 – Ernst Curtius, German archaeologist and historian (d. 1896)
September 3 – James Joseph Sylvester, English mathematician (d. 1897)
September 6 – George-Étienne Cartier, Canadian lawyer and politician (d. 1873)
September 7 – William Butterfield, British architect (d. 1900)
September 8 – Charles Étienne Brasseur de Bourbourg, French writer and historian (d. 1874)
September 27 – Daniel Kirkwood, American astronomer (d. 1895)
October 1 – Josefina Deland, Swedish women's rights activist (d. 1890)
October 4 – Jean-François Millet, French painter (d. 1875)
October 7 – Susanna Dickinson, survivor of the Alamo (d. 1883)
October 15 – Mikhail Lermontov, Russian writer (d. 1841)
November 6 – Adolphe Sax, Belgian musical instrument maker and inventor (d. 1894)
November 13 – Joseph Hooker, American general (d. 1879)
November 22 – Serranus Clinton Hastings, American politician (d. 1893)
November 25 – Julius von Mayer, German physician and physicist and one of the founders of thermodynamics (d. 1878)
November 26 – Luise Aston, German author and feminist (d. 1871)
December 13 – Ana Néri, Brazilian nurse, matron of nursing in that country (d. 1880)
December 18 – Sarah T. Bolton, née Sarah Tittle Barrett, American poet (d. 1893)
Táhirih, Persian Bahá'í heroine (d. 1852)
Pavlos Kalligas, Greek jurist and politician (d. 1896)
Ann Leah Underhill, one of the Fox sisters (d. 1890)
Antoinette Nording, Swedish perfume entrepreneur (d. 1887)
January 7 – Ira Allen, founder of Vermont and leader of the Green Mountain Boys (born 1751)
Philip Astley, English circus promoter (born 1742)
Johann Gottlieb Fichte, German philosopher (born 1762)
February 27 – Margaret Bingham British Countess, painter and writer (born 1740)
March 26 – Joseph-Ignace Guillotin, French physician (born 1738)
April 1 – Joseph de Ferraris, Austrian cartographer of the Austrian Netherlands (born 1726)
April 12 – Charles Burney, English music historian (born 1726)
April 19 – Thomas Brudenell-Bruce, 1st Earl of Ailesbury, English earl (born 1729)
May 5 – Abdullah I Al-Sabah, Kuwaiti ruler (born 1740)
May 6 – Stephen Amherst, English cricketer (born 1750)
May 27 – Ivan Akimov, Russian painter (born 1754)
May 29 – Joséphine de Beauharnais, Empress of France (born 1763)
June 14 – Antin Angelovych, Greek-Catholic metropolitan (born 1756)
July 12 – William Howe, 5th Viscount Howe, British general
July 18 – Miles Peter Andrews, English playwright and legislator (born 1742)
July 19 – Captain Matthew Flinders, English explorer of the coasts of Australia (b. 1774)
Antonio Carnicero, Spanish painter (b. 1748)
Benjamin Thompson, American physicist and inventor (b. 1753)
August 28 – Erik Must Angell, Norwegian jurist and politician (born 1744)
August 31 – Arthur Phillip, British admiral and first governor of New South Wales (b. 1738)
September 8 – Maria Carolina of Austria, queen of Ferdinand I of the Two Sicilies, and de facto ruler (b. 1752)
October 4 – Samuel Jackson Pratt, British writer, poet and actor (b. 1749)
October 19 – Mercy Otis Warren, American playwright (b. 1728)
November 18 – Aleijadinho, Colonial Brazil-born sculptor and architect (b. 1730 or 1738)
November 23 – Elbridge Gerry, 5th Vice President of the United States (b. 1744)
December 2 – Marquis de Sade, French writer (b. 1740)
December 13 – Charles-Joseph, 7th Prince of Ligne, Austrian field marshal (b. 1735)
December 19 – Joseph Bramah, inventor of the hydraulic press (b. 1748)
1814 (MDCCCXIV) was a common year starting on Saturday (dominical letter B) of the Gregorian calendar and a common year starting on Thursday (dominical letter D) of the Julian calendar, the 1814th year of the Common Era (CE) and Anno Domini (AD) designations, the 814th year of the 2nd millennium, the 14th year of the 19th century, and the 5th year of the 1810s decade. As of the start of 1814, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.