|Covid-19|January 5 – The first regatta in Australia is held, taking place on Tasmania (called at the time, "Van Diemen's Land") on the River Derwent at Hobart.
January 15 – Furman University, founded in 1826, begins its first classes with 10 students, as the Furman Academy and Theological Institution, located at Edgefield, South Carolina. By the end of 2016, it would have 2,800 students at its main campus in Greenville, South Carolina.
January 27 – Author Johann Wolfgang von Goethe first elaborated on his vision of Weltliteratur (world literature) in a letter to Johann Peter Eckermann, declaring his belief that "poetry is the universal possession of mankind", and that "the epoch of world literature is at hand, and each must work to hasten its coming."
February 20 – Battle of Ituzaingo (Passo do Rosário): A force of the Brazilian Imperial Army meets Argentine–Uruguayan troops in combat.
February 28 – The Baltimore & Ohio Railroad is incorporated, becoming the first railroad in United States offering commercial transportation of both people and freight.
March 7 – Brazilian marines sail up the Rio Negro and attack the temporary naval base of Carmen de Patagones, Argentina; they are defeated by the local citizens.
March 7 – Shrigley Abduction: Ellen Turner, a wealthy heiress in Cheshire, England, is abducted by Edward Gibbon Wakefield, the future politician in colonial New Zealand.
March 11 – The new state constitution for the Mexican state of Coahuila y Tejas is ratified, including a phasing-out of slavery in its Article 13, which declares that "From and after the promulgation of the constitution in the capital of each district, no one shall be born a slave in the state, and after six months the introduction of slaves under any pretext shall not be permitted." The prohibition of importing slaves from the United States will be lifted when Texas declares independence in 1836, and the Republic of Texas Constitution will provide specifically that Africans and "the descendants of Africans" will not be considered "citizens of the republic".
March 16 – Freedom's Journal, the first African-American owned and published newspaper in the United States, is founded in New York City by John Russwurm.
March 26 – German composer Ludwig van Beethoven dies in Vienna after a prolonged illness.
April 7–April 8 – Battle of Monte Santiago: A squadron of the Brazilian Imperial Navy defeats Argentine vessels in a major naval engagement.
April 10 – UK: George Canning succeeds Lord Liverpool as British Prime Minister.
April 24 – Greek War of Independence – Battle of Phaleron: Ottoman troops defeat the Greek rebels.
April 26–May 24 – The Royal Netherlands Navy's British-built paddle steamer Curaçao makes the first Transatlantic Crossing by steam, from Hellevoetsluis to Paramaribo.
April 29 – The Fly Whisk Incident in Ottoman Algeria: Hussein Dey slaps the French consul Pierre Deval on the face, eventually leading to Invasion of Algiers in 1830.
May 20–July 9 – Zarafa, a giraffe presented by the Ottoman Viceroy of Egypt, Mehmet Ali Pasha, to King Charles X of France, the first to be seen in Europe for over three centuries, walks from Marseilles to Paris.
May 21 – The Maryland Democratic Party is founded by supporters of Andrew Jackson in Baltimore and hosts its first meeting at the Baltimore Atheneum.
May 25 – Romanian inventor Petrache Poenaru receives a French patent for the invention of the first fountain pen with a replaceable ink cartridge.
June 4 – French inventor Joseph Niépce sends a package to Louis Daguerre, revealing the existence of his invention, "heliography", where an image can be reproduced on to a pewter plate and then reprinted. In 1829, the two will begin a partnership and Daguerre will perfect Niépce's photographic process to reproduce images more quickly.
June 7 – Greek defenders in Athens surrender to Egyptian forces under the command of General Rashid Pasha.
July 6 – Greek War of Independence: The Treaty of London between France, Britain, and Russia, demands that the Turks agree to an armistice in Greece.
July 14 – The Roman Catholic Diocese of Honolulu is founded in the Kingdom of Hawaii.
August 31 – UK: Frederick John Robinson, 1st Viscount Goderich, becomes Prime Minister of the UK, following the death of George Canning.
September 4 – Finland: The Great Fire of Turku destroys 3/4 of the city, with many human casualties.
September 20 – Petition for a land grant for 215 acres on the north bank of Rio Grande just across from Paso del Norte (present day Ciudad Juárez) is approved; first residence is built on what is present day El Paso, Texas.
September 22 – Joseph Smith claimed in 1838 that on this day he had taken the Golden plates from the place where they were stored, and that he began writing down the Book of Mormon from them the following December.
October 1 – Russo-Persian War, 1826-1828: The Russians under Ivan Paskevich storm Yerevan, ending a millennium of Muslim domination in Eastern Armenia.
October 20 – Greek War of Independence – Battle of Navarino: British, French, and Russian naval forces destroy the Turko-Egyptian fleet in Greece. This is the last naval action to be fought under sail alone.
November – The term "socialist" is coined by Robert Owen in his London periodical, The Co-operative Magazine and Monthly Herald.
November 24 – Voting is completed in elections for France's 430 member Chamber of Deputies. The Ultraroyalistes, supporters of King Charles X, lose their 233-seat majority and finish with 180 seats, the same number as the opposition Doctrinaires.
December 20 – Mexico passes its first "expulsion law", providing for citizens of Spain to be expelled within the next six months, and to remain barred from re-entry until the Kingdom of Spain recognizes Mexico's 1810 declaration of independence. Ultimately, because of all the exemptions within the expulsion act, only 1,779 of the 6,610 Spaniards are required to leave.
Laos: King Anouvong of Vientiane leads the Laotian Rebellion against Siam and successfully attacks Nakhon Ratchasima (the Siamese later invade Vientiane and nearly destroy the whole city).
Englishman John Walker invents the first friction match which he names Lucifer.
Egypt: Cairo University School of Medicine is established as the first African medical school in the Middle East.
John James Audubon begins publication of the 10-volume The Birds of America in the United Kingdom.
January 7 – Sir Sandford Fleming, Scottish-Canadian engineer and inventor (d. 1915)
January 28 – Jean Antoine Villemin, French physician (d. 1892)
February 17 – Elisabeth Blomqvist, Swedish-Finnish educator and feminist (d. 1901)
March 7 – John Hall Gladstone, English chemist (d. 1902)
March 8 – Wilhelm Bleek, German linguist (d. 1875)
March 25 – Stephen Luce, American admiral (d. 1917)
April 2 – William Holman Hunt, British Pre-Raphaelite painter (d. 1910)
April 5 – Joseph Lister, English surgeon (d. 1912)
April 8 – Ramón Emeterio Betances, Puerto Rican politician, medical doctor and diplomat (d. 1898)
May 11 – Jean-Baptiste Carpeaux, French sculptor and painter (d. 1875)
May 19 – Paul-Armand Challemel-Lacour, French statesman (d. 1896)
May 21 – William P. Sprague, American politician from Ohio (d. 1899)
May 27 – Samuel F. Miller, American politician (d. 1892)
May 31 – Frederic Thesiger, 2nd Baron Chelmsford, British general (d. 1905)
June 11 – Natalie Zahle, Danish educator and women's rights activist (d. 1913)
June 12 – Johanna Spyri, Swiss author (d. 1901)
June 13 – Alberto Henschel, German-Brazilian photographer and businessman (d. 1882)
June 24 – Louis Brière de l'Isle, French general (d. 1897)
June 26 – Amédée Courbet, French admiral (d. 1885)
July 13 – Hugh O'Brien, Mayor of Boston (d. 1895)
July 17 – Sir Frederick Augustus Abel, British chemist (d. 1902)
July 18 – Mangal Pandey, Indian soldier (d. 1857)
July 24 – Francisco Solano López, president of Paraguay (d. 1870)
September 3 – John Drew Sr., Irish-American stage actor & manager, (d. 1862)
September 30 – Ellis H. Roberts, American politician (d. 1918)
October 12 – Josiah Parsons Cooke, American chemist (d. 1894)
October 25 – Marcellin Berthelot, French chemist (d. 1907)
November 7 – Antti Ahlström, Finnish industrialist (d. 1896)
November 9 – Carl Friedrich Claus, German chemist (d. 1900)
November 10 – J.T. Wamelink, American composer (d. 1910)
November 18 – Mehmed Ali Pasha, Prussian-born Ottoman military leader (d. 1878)
November 26 – Ellen G. White, American religious leader (d. 1915)
December 3 – Jain Acharya Rajendrasuri, religious reformer (d. 1906)
December 17 – Baron Alexander Wassilko von Serecki, Governor of the Duchy of Bucovina and member of the Herrenhaus (d. 1893)
December 23 – Wilhelm von Tegetthoff, Austrian admiral (d. 1871)
undated – Amanda Cajander, Finnish medical reformer (d. 1871)
January 5 – Prince Frederick, Duke of York and Albany, heir-presumptive to the British throne (b. 1763)
January 19 – Ludwig von Brauchitsch, Prussian general (b. 1757)
February 19 – Armand Augustin Louis de Caulaincourt, French general and diplomat (b. 1773)
February 23 – Felipe Enrique Neri, legislator and colonizer of Texas (b. 1759)
February 28 – Thomas Holloway, English portrait painter and engraver (b. 1748)
Pierre-Simon Laplace, French mathematician (b. 1749)
Alessandro Volta, Italian physicist (b. 1745)
March 26 – Ludwig van Beethoven, German composer (b. 1770)
March 31 – Marie Barch, Danish ballerina (b. 1744)
April 12 – Michele Troja, Italian physician (b. 1747)
Deborah Sampson, first American female soldier (b. 1760)
Rufus King, American lawyer, politician, and diplomat (b. 1755)
May 27 – Melesina Trench, Irish born writer and socialite (b. 1768)
July 14 – Augustin-Jean Fresnel, French physicist (b. 1788)
August 8 – George Canning, Prime Minister of the United Kingdom (b. 1770)
August 12 – William Blake, English poet and artist (b. 1757)
September 10 – Ugo Foscolo, Greece-born Italian writer, revolutionary and poet (b. 1778)
November 7 – Maria Theresia of Tuscany, Queen of Saxony (b. 1767)
December 3 – Servando Teresa de Mier, preacher (b. 1765)
December 21 – Anton II, Catholicos Patriarch of Georgia (b. 1762)
1827 (MDCCCXXVII) was a common year starting on Monday (dominical letter G) of the Gregorian calendar and a common year starting on Saturday (dominical letter B) of the Julian calendar, the 1827th year of the Common Era (CE) and Anno Domini (AD) designations, the 827th year of the 2nd millennium, the 27th year of the 19th century, and the 8th year of the 1820s decade. As of the start of 1827, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.