|Covid-19|January 7 – The first group of freed slaves from the United States arrive to the west coast of Africa, founding Monrovia on April 25.
January 13 – The design of the modern-day flag of Greece is adopted by the First National Assembly at Epidaurus for their naval flag.
February 6 – Chinese junk Tek Sing sinks in the South China Sea with the loss of around 1600 people on board.
February 9 – The invading Haitian forces led by Jean-Pierre Boyer arrive in Santo Domingo to overthrow the newly founded Dominican Republic.
February 24 – The first Swaminarayan temple, Kalupur Swaminarayan Mandir at Ahmedabad in the British Raj, is inaugurated.
March 31 – Greek War of Independence: Start of Chios massacre, during which 20,000 Greeks on the island of Chios are slaughtered by Ottoman troops and 23,000 exiled.
May 24 – Battle of Pichincha: Simón Bolívar secures the independence of Quito.
May 25 – Execution of Christos Palaskas and Alexis Noutsos by Odysseas Androutsos' forces.
May 26 – 116 people die in the Grue Church fire, the biggest fire disaster in Norway's history.
June 6 – Alexis St. Martin accidentally shot in the stomach, which leads the way to William Beaumont's studies on digestion.
July 3 – Charles Babbage publishes a proposal for a "difference engine", a forerunner of the modern computer for calculating logarithms and trigonometric functions. Construction of an operational version will proceed under British Government sponsorship 1823–32 but it will never be completed.
July 8 – The Chippewas turn over a huge tract of land in Ontario to the United Kingdom.
July 13 – Greek War of Independence: Greeks defeat Ottoman forces at Thermopylae.
July 26 – Guayaquil Conference: José de San Martín arrives in Guayaquil, Ecuador, to meet with Simón Bolívar.
July 27 – Guayaquil Conference: Simón Bolívar and General José de San Martín meet in Guayaquil, which Bolívar later annexes.
July 31 – The last public whipping is carried out in Edinburgh.
August 12 – St David's College (the modern-day University of Wales, Lampeter) is founded in Wales by Thomas Burgess, Bishop of St David's.
August 15–29 – Visit of King George IV to Scotland.
August 22 – The English ship Orion lands at Yerba Buena, now named San Francisco, under the command of William A. Richardson.
September 7 – Brazilian independence: Brazil declares its independence from Portugal.
September 8–13 – Battle of Nauplia: In a series of naval engagements the Ottoman Fleet fails to break through the Greek Fleet under Admiral Andreas Vokos Miaoulis
September 11 – Galileo Galilei's Dialogue Concerning the Two Chief World Systems (1632) is permitted by the Roman Catholic Church to be published.
George Canning is appointed British Secretary of State for Foreign Affairs.
Constituent Congress of Peru begins its first session.
September 22 – Portugal approves its first Constitution.
September 27 – Jean-François Champollion announces his success in deciphering Egyptian hieroglyphs using the Rosetta Stone in a letter to the Académie des Inscriptions et Belles-Lettres in Paris (based on the work of Thomas Young).
October 12 – Pedro I of Brazil is declared the constitutional Emperor of Brazil.
October 31 – Emperor Agustín de Iturbide of the First Mexican Empire dissolves the country's Congress of the Union and replaces it with a military junta.
October–December – Congress of Verona: Russia, Austria and Prussia approve French intervention in Spain.
November 9 – Action of 9 November 1822: USS Alligator (1820) engages three pirate schooners off Cuba as part of the West Indies anti-piracy operations of the United States.
Greek War of Independence: Nafplio falls to the Greek rebels.
Congregation of St. Basil founded in France.
November 19 – An earthquake near Valparaíso in Chile kills around 200, causes a tsunami and raises the coastal area.
December 1 – Pedro I is crowned as first Emperor of Brazil.
The Rocky Mountain Fur Company ("Ashley's Hundred") leave from St. Louis, Missouri, setting off a major increase in fur trade.
Coffee is no longer banned in Sweden.
January 2 – Rudolf Clausius, German physicist (d. 1888)
January 6 – Heinrich Schliemann, German archaeologist (d. 1890)
January 9 – Carol Benesch, Silesian and Romanian architect (d. 1896)
January 12 – Étienne Lenoir, Belgian engineer (d. 1900)
January 25 – Charles Reed Bishop, preeminent businessman and philanthropist in Hawaii (d. 1915)
January 28 – Alexander Mackenzie, 2nd Prime Minister of Canada (d. 1892)
February 4 – Edward Fitzgerald Beale, American Navy Lieutenant and explorer (d. 1893)
February 16 – Sir Francis Galton, English explorer and biologist (d. 1911)
c. March – Harriet Tubman, born Araminta Ross, African-American abolitionist, humanitarian and spy (d. 1913)
March 4 – Jules Antoine Lissajous, French mathematician (d. 1880)
April 3 – Edward Everett Hale, American writer (d. 1909)
April 16 – Robert Luther, German astronomer (d. 1900)
April 26 – Frederick Law Olmsted, American landscape architect (d. 1903)
April 27 – Ulysses S. Grant, 18th President of the United States (d. 1885)
May 18 – Mathew Brady, American photographer (d. 1896)
May 20 – Frédéric Passy, French economist, recipient of the Nobel Peace Prize (d. 1912)
May 26 – Edmond de Goncourt, French writer (d. 1896)
May 11 – Henry Baker Tristram, English clergyman, and ornithologist. (d. 1906)
June 10 – John Jacob Astor III, American businessman (d. 1890)
July 4 – Jean-Baptiste Claude Eugène Guillaume, French sculptor (d. 1905)
July 18 – Princess Augusta of Cambridge (d. 1916)
July 20 – Gregor Mendel, Czech geneticist (d. 1884)
July 21 – Alexander H. Jones, Congressional Representative from North Carolina. (d. 1901)
July 25 – Andrew Bryson, American admiral (d. 1892)
October 4 – Rutherford B. Hayes, 19th President of the United States (d. 1893)
October 6 – Benjamin F. Isherwood, American admiral and United States Navy Engineer-in-Chief (d. 1915)
December 10 – César Franck, Belgian composer and organist (d. 1890)
December 24 – Matthew Arnold, English poet (d. 1888)
December 27 – Louis Pasteur, French microbiologist and chemist (d. 1895)
January 10 – Bathilde d'Orléans, French princess (b. 1750)
January 16 – Elisabeth Berenberg, German banker (b. 1749)
January 21 – Marie-Aimée Lullin, Swiss entomologist (b. 1751)
January 24 – Ali Pasha of Yanina, ruler of European Turkey (b. 1741)
February 10 – Prince Albert of Saxony, Duke of Teschen (b. 1738)
February 24 – Thomas Coutts, banker (b. 1735)
February 27 – Sir John Borlase Warren, 1st Baronet, admiral (b. 1753)
April 14 – Edmund Butcher, minister (b. 1757)
April 20 – Allegra Byron, illegitimate daughter of Lord Byron (b. 1817)
May 27 – Augustus, Duke of Saxe-Gotha-Altenburg (b. 1772)
June 25 – E. T. A. Hoffmann, German Romantic author (b. 1776)
July 8 – Percy Bysshe Shelley, English poet (b. 1792)
August 4 – Kristjan Jaak Peterson, Estonian poet (b. 1801)
August 12 – Robert Stewart, Viscount Castlereagh, British foreign secretary (suicide) (b. 1769)
August 25 – William Herschel, German-born astronomer (b. 1738)
September 8 – Sophie de Condorcet, politically active French salonist and feminist (b. 1764)
October 26 – Mahmud Dramali Pasha, Ottoman vizier (b. c. 1780)
October 31 – Jared Ingersoll, U.S. presidential candidate (b. 1749)
November 24– Zofia Potocka, Greek-Polish noble and agent (b. 1760)
date unknown – Manuela Medina, Mexican national heroine (b. 1780)
Sara Oust, Norwegian lay minister (b. 1778)
1822 (MDCCCXXII) was a common year starting on Tuesday (dominical letter F) of the Gregorian calendar and a common year starting on Sunday (dominical letter A) of the Julian calendar, the 1822nd year of the Common Era (CE) and Anno Domini (AD) designations, the 822nd year of the 2nd millennium, the 22nd year of the 19th century, and the 3rd year of the 1820s decade. As of the start of 1822, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.