September 21

Pre-1600

• 455 – Emperor Avitus enters Rome with a Gallic army and consolidates his power.
• 1170 – The Kingdom of Dublin falls to Norman invaders.
• 1217 – Livonian Crusade: The Estonian leader Lembitu and Livonian leader Kaupo the Accursed are killed in the Battle of St. Matthew's Day.
• 1435 – The Congress of Arras causes Burgundy to switch sides in the Hundred Years' War.

1601–1900

• 1745 – A Hanoverian army is defeated, in ten minutes, by the Jacobite forces of Prince Charles Edward Stuart.
• 1776 – Part of New York City is burned shortly after being occupied by British forces.
• 1780 – American Revolutionary War: Benedict Arnold gives the British the plans to West Point.
• 1792 – French Revolution: The National Convention abolishes the monarchy.
• 1809 – British Secretary of War Lord Castlereagh and Foreign Secretary George Canning meet in a duel on Putney Heath, with Castlereagh wounding Canning in the thigh.
• 1843 – The crew of schooner Ancud, led by John Williams Wilson, takes possession of the Strait of Magellan on behalf of the Chilean government.
• 1860 – Second Opium War: An Anglo-French force defeats Chinese troops at the Battle of Palikao.
• 1862 – Taiping Rebellion: The Ever Victorious Army defeats Taiping forces at the Battle of Cixi.
• 1896 – Anglo-Egyptian conquest of Sudan: British forces under the command of Horatio Kitchener take Dongola.
• 1898 – Empress Dowager Cixi seizes power and ends the Hundred Days' Reform in China.

1901–present

• 1921 – A storage silo in Oppau, Germany, explodes, killing 500–600 people.
• 1933 – Salvador Lutteroth establishes Mexican professional wrestling.
• 1934 – A large typhoon hits western Honshū, Japan, killing more than 3,000 people.
• 1938 – The Great Hurricane of 1938 makes landfall on Long Island in New York. The death toll is estimated at 500–700 people.
• 1939 – Romanian Prime Minister Armand Călinescu is assassinated by the Iron Guard.
• 1942 – The Holocaust in Ukraine: On the Jewish holiday of Yom Kippur, Nazis send over 1,000 Jews of Pidhaitsi to Bełżec extermination camp.
• 1942 – The Holocaust in Ukraine: In Dunaivtsi, Ukraine, Nazis murder 2,588 Jews.
• 1942 – The Holocaust in Poland: At the end of Yom Kippur, Germans order Jews to permanently move from Konstantynów to Biała Podlaska.
• 1942 – The Boeing B-29 Superfortress makes its maiden flight.
• 1953 – Lieutenant No Kum-sok, a North Korean pilot, defects to South Korea with his jet fighter.
• 1957 – Pamir, a four-masted barque, was shipwrecked and sank off the Azores during Hurricane Carrie.
• 1964 – Malta gains independence from the United Kingdom, but remains in the Commonwealth.
• 1964 – The North American XB-70 Valkyrie, the world's fastest bomber, makes its maiden flight from Palmdale, California.
• 1965 – The Gambia, Maldives and Singapore are admitted as members of the United Nations.
• 1971 – Bahrain, Bhutan and Qatar join the United Nations.
• 1972 – Philippine President Ferdinand Marcos begins authoritarian rule by declaring martial law.
• 1976 – Orlando Letelier is assassinated in Washington, D.C at the order of Augusto Pinochet.
• 1976 – Seychelles joins the United Nations.
• 1981 – Belize is granted full independence from the United Kingdom.
• 1981 – Sandra Day O'Connor is unanimously approved by the U.S. Senate as the first female Supreme Court justice.
• 1984 – Brunei joins the United Nations.
• 1991 – Armenia gains independence from the Soviet Union.
• 1993 – Russian President Boris Yeltsin triggers a constitutional crisis when he suspends parliament and scraps the constitution.
• 1993 – A Transair Georgian Airlines Tu-134 is shot down by a missile in the Black Sea near Sukhumi, Georgia.
• 1996 – The Defense of Marriage Act is passed by the United States Congress.
• 1997 – St. Olaf's Church, a stone church from the 16th century in Tyrvää, Finland, is burnt down by a burglar.
• 1999 – The Chi-Chi earthquake occurs in central Taiwan, leaving about 2,400 people dead.
• 2001 – America: A Tribute to Heroes is broadcast by over 35 network and cable channels, raising over $200 million for the victims of the September 11 attacks.
• 2001 – Ross Parker is murdered in Peterborough, England, by a gang of ten British Pakistani youths.
• 2003 – The Galileo spacecraft is terminated by sending it into Jupiter's atmosphere.
• 2012 – Three Egyptian militants open fire on a group of Israeli soldiers in a southern Israel cross-border attack.
• 2013 – Al-Shabaab Islamic militants attack the Westgate shopping mall in Kenya, killing at least 67 people.
• 2015 – Adventist Health System agreed to pay $118.7 million to settle allegations of fraud. It was the largest a hospital network has ever paid.
• 2018 – Killing of Zak Kostopoulos, LGBT rights activist beaten to death on a busy street in Athens
• 2019 – A 5.6 M_w earthquake shakes the Albanian port of Durrës. Forty-nine people are injured in the capital, Tirana.

Pre-1600

• 580 – Pope Vitalian (d. 672)
• 953 – Abu Ishaq Ibrahim, Buyid prince
• 1051 – Bertha of Savoy (d. 1087)
• 1371 – Frederick I, Elector of Brandenburg (d. 1440)
• 1407 – Leonello d'Este, Marquis of Ferrara, Italian noble (d. 1450)
• 1411 – Richard of York, 3rd Duke of York, English politician, Lord Protector of England (d. 1460)
• 1415 – Frederick III, Holy Roman Emperor (d. 1493)
• 1428 – Jingtai Emperor of China (d. 1457)
• 1433 – Guillaume Fichet, French scholar and academic (d. 1480)
• 1452 – Girolamo Savonarola, Italian priest and philosopher (d. 1498)
• 1457 – Hedwig Jagiellon, Duchess of Bavaria, Polish princess (d. 1502)
• 1552 – Barbara Longhi, Italian painter (d. 1638)
• 1559 – Cigoli, Italian painter and architect (d. 1613)

1601–1900

• 1629 – Philip Howard, English cardinal (d. 1694)
• 1640 – Philippe I, Duke of Orléans, younger son of Louis XIII of France and his wife (d. 1701)
• 1645 – Louis Jolliet, Canadian explorer (d. 1700)
• 1706 – Polyxena of Hesse-Rotenburg (d. 1735)
• 1758 – Christopher Gore, American soldier, lawyer, and politician, 8th Governor of Massachusetts (d. 1827)
• 1760 – Ivan Dmitriev, Russian poet and politician, Minister of Justice for Imperial Russia (d. 1837)
• 1776 – John Fitchett, English poet (d. 1838)
• 1819 – Princess Louise Marie Thérèse of Artois (d. 1864)
• 1840 – Murad V, Ottoman sultan (d. 1904)
• 1842 – Abdul Hamid II, 34th Sultan of the Ottoman Empire (d. 1918)
• 1846 – Mihály Kolossa, Hungarian-Slovene author and poet (d. 1906)
• 1849 – Maurice Barrymore, American actor (d. 1905)
• 1851 – Fanny Searls, American biologist (d. 1939)
• 1853 – Heike Kamerlingh Onnes, Dutch physicist and academic, Nobel Prize laureate (d. 1926)
• 1859 – Francesc Macià, Catalan colonel and politician, 122nd President of Catalonia (d. 1933)
• 1862 – James E. Talmage, English-American religious leader and author (d. 1933)
• 1863 – John Bunny, American actor (d. 1915)
• 1866 – Charles Nicolle, French-Tunisian microbiologist and academic, Nobel Prize laureate (d. 1936)
• 1866 – H. G. Wells, English novelist, historian, and critic (d. 1946)
• 1867 – Charles Bathurst, 1st Viscount Bledisloe, English politician, 4th Governor-General of New Zealand (d. 1958)
• 1867 – Henry L. Stimson, American colonel, lawyer, and politician, 46th United States Secretary of State (d. 1950)
• 1872 – Henry Tingle Wilde, English chief officer on the RMS Titanic (d. 1912)
• 1873 – Papa Jack Laine, American drummer and bandleader (d. 1966)
• 1874 – Gustav Holst, English composer and educator (d. 1934)
• 1878 – Peter McWilliam, Scottish-English footballer and manager (d. 1951)
• 1882 – Geevarghese Ivanios, Indian metropolitan (d. 1953)
• 1884 – Dénes Kőnig, Hungarian mathematician and theorist (d. 1944)
• 1890 – Max Immelmann, German lieutenant and pilot (d. 1916)
• 1890 – Charles William Train, English sergeant, Victoria Cross recipient (d. 1965)
• 1893 – Erna Scheffler, German lawyer and justice of the Federal Constitutional Court (d. 1983)
• 1894 – Anton Piëch, Austrian lawyer and businessman (d. 1952)
• 1898 – Frances Mary Albrier, American civil rights activist (d. 1987)
• 1899 – Frederick Coutts, Scottish 8th General of The Salvation Army (d. 1986)

1901–present

• 1902 – Luis Cernuda, Spanish poet and critic (d. 1963)
• 1902 – Allen Lane, English publisher, founded Penguin Books (d. 1970)
• 1902 – Howie Morenz, Canadian ice hockey player (d. 1937)
• 1903 – Preston Tucker, American engineer and businessman, designed the Tucker Sedan (d. 1956)
• 1904 – Hans Hartung, German-French painter (d. 1989)
• 1905 – Robert Lebel, Canadian businessman and politician (d. 1999)
• 1906 – Henry Beachell, American biologist and botanist (d. 2006)
• 1909 – Kwame Nkrumah, Ghanaian educator and politician, 1st President of Ghana (d. 1972)
• 1910 – Meinrad Schütter, Swiss composer (d. 2006)
• 1912 – Chuck Jones, American animator, producer, and screenwriter (d. 2002)
• 1912 – György Sándor, Hungarian pianist and composer (d. 2005)
• 1916 – Françoise Giroud, Swiss-French journalist and politician, French Minister of Culture (d. 2003)
• 1917 – Phyllis Nicolson, English mathematician and academic (d. 1968)
• 1918 – John Gofman, American physicist, chemist, and biologist (d. 2007)
• 1918 – Karl Slover, American actor (d. 2011)
• 1918 – Juan José Arreola, Mexican writer and academic (d. 2001)
• 1919 – Mario Bunge, Argentinian-Canadian physicist and philosopher (d. 2020)
• 1919 – Herman Fowlkes, Jr., American trumpet player and educator (d. 1993)
• 1919 – Fazlur Rahman Malik, Pakistani philosopher and scholar (d. 1988)
• 1920 – Kenneth McAlpine, British race car driver (d. 2023)
• 1921 – John McHale, American baseball player and manager (d. 2008)
• 1923 – Fred Hunt, British jazz pianist (d. 1986)
• 1924 – Hermann Buhl, Austrian mountaineer (d. 1957)
• 1926 – Don Dunstan, Fijian-Australian lawyer and politician, 35th Premier of South Australia (d. 1999)
• 1926 – Donald A. Glaser, American physicist and neurobiologist, Nobel Prize laureate (d. 2013)
• 1926 – Fereydoon Moshiri, Iranian poet and critic (d. 2000)
• 1929 – Sándor Kocsis, Hungarian footballer and manager (d. 1979)
• 1929 – Edgar Valter, Estonian author and illustrator (d. 2006)
• 1929 – Bernard Williams, English-Italian philosopher and academic (d. 2003)
• 1930 – John Morgan, Welsh-Canadian actor and screenwriter (d. 2004)
• 1930 – Bob Stokoe, English footballer and manager (d. 2004)
• 1931 – Larry Hagman, American actor, director, and producer (d. 2012)
• 1932 – Shirley Conran, English journalist and author
• 1932 – Marjorie Fletcher, English Director of the Women's Royal Naval Service (d. 2008)
• 1932 – Don Preston, American keyboard player and composer
• 1933 – Allan Jeans, Australian footballer and coach (d. 2011)
• 1933 – Dick Simon, American race car driver
• 1934 – Leonard Cohen, Canadian singer-songwriter and poet (d. 2016)
• 1934 – María Rubio, Mexican actress (d. 2018)
• 1935 – Jimmy Armfield, English footballer and manager (d. 2018)
• 1935 – Henry Gibson, American actor (d. 2009)
• 1936 – Ian Albery, English manager and producer
• 1936 – Dickey Lee, American pop-country singer-songwriter and guitarist
• 1936 – Yury Luzhkov, Russian soldier and politician, 2nd Mayor of Moscow (d. 2019)
• 1936 – Diane Rehm, American journalist and radio host
• 1937 – John D'Amico, Canadian ice hockey player and referee (d. 2005)
• 1938 – Doug Moe, American basketball player and coach
• 1938 – Olu Falae, Nigerian politician and government official
• 1939 – Agnivesh, Indian philosopher, academic, and politician
• 1940 – Ron Fenton, English footballer, coach, and manager (d. 2013)
• 1940 – Hermann Knoflacher, Austrian engineer and academic
• 1940 – Bill Kurtis, American journalist and producer
• 1941 – Jack Brisco, American wrestler and manager (d. 2010)
• 1941 – R. James Woolsey, Jr., American scholar and diplomat, 16th Director of Central Intelligence
• 1942 – Sam McDowell, American baseball player
• 1943 – David Hood, American session bassist and trombone player
• 1943 – Jerry Bruckheimer, American film and television producer
• 1944 – Steve Beshear, American lawyer and politician, 61st Governor of Kentucky
• 1944 – Marcus Binney, English historian and author
• 1944 – Fannie Flagg, American actress, comedian, and author
• 1944 – Hamilton Jordan, American politician, 8th White House Chief of Staff (d. 2008)
• 1944 – Bobby Tench, English singer-songwriter and guitarist (d. 2024)
• 1945 – Richard Childress, American race car driver and businessman
• 1945 – Shaw Clifton, Northern Irish 18th General of The Salvation Army
• 1945 – Kay Ryan, American poet and educator
• 1946 – Rose Garrard, English sculptor and author
• 1946 – Moritz Leuenberger, Swiss lawyer and politician, 87th President of the Swiss Confederation
• 1946 – Mart Siimann, Estonian psychologist and politician, 12th Prime Minister of Estonia
• 1947 – Don Felder, American musician and songwriter
• 1947 – Keith Harris, English ventriloquist and singer (d. 2015)
• 1947 – Rupert Hine, English musician, songwriter, and record producer (d. 2020)
• 1947 – Stephen King, American author and screenwriter
• 1947 – Ed Nimmervoll, Austrian-Australian journalist, historian, and author (d. 2014)
• 1947 – Marsha Norman, American playwright and author
• 1948 – Jack Dromey, English union leader and politician (d. 2022)
• 1948 – Mitsuo Momota, Japanese wrestler
• 1949 – Henry Butler, American pianist and photographer (d. 2018)
• 1949 – Artis Gilmore, American basketball player and radio host
• 1949 – Odilo Scherer, Brazilian cardinal
• 1950 – Charles Clarke, English economist and politician, Secretary of State for Education
• 1950 – Bill Murray, American actor, comedian, producer, and screenwriter
• 1951 – Bruce Arena, American soccer player and manager
• 1951 – Aslan Maskhadov, Chechen general and politician, 3rd President of the Chechen Republic of Ichkeria (d. 2005)
• 1952 – Dave Gregory, English guitarist and keyboard player
• 1952 – John Taylor, Baron Taylor of Warwick, English lawyer and politician
• 1953 – Arie Luyendyk, Dutch race car driver and sportscaster
• 1953 – Reinhard Marx, German cardinal
• 1954 – Shinzo Abe, Japanese lawyer and politician, 90th Prime Minister of Japan (d. 2022)
• 1954 – Thomas S. Ray, American ecologist and academic
• 1954 – Phil "Philthy Animal" Taylor, English rock drummer (d. 2015)
• 1955 – Richard Hieb, American engineer and astronaut
• 1955 – Israel Katz, Israeli politician
• 1955 – Mika Kaurismäki, Finnish director, producer, and screenwriter
• 1956 – Jack Givens, American basketball player and sportscaster
• 1956 – Marta Kauffman, American screenwriter and producer
• 1956 – Ricky Morton, American wrestler
• 1957 – Ethan Coen, American director, producer, and screenwriter
• 1957 – Mark Levin, American lawyer, radio host, and author
• 1957 – Sidney Moncrief, American basketball player and coach
• 1957 – Kevin Rudd, Australian politician and diplomat, 26th Prime Minister of Australia
• 1958 – Rick Mahorn, American basketball player and coach
• 1958 – Simon Mayo, English radio host
• 1959 – Crin Antonescu, Romanian educator and politician, former Interim President of Romania
• 1959 – Andrzej Buncol, Polish footballer
• 1959 – Dave Coulier, American actor, comedian, producer, and screenwriter
• 1959 – Danny Cox, English-American baseball player and coach
• 1959 – Corinne Drewery, English singer-songwriter and fashion designer
• 1960 – David James Elliott, Canadian-American actor and director
• 1960 – Masoumeh Ebtekar, Iranian journalist, politician and scientist, first woman Vice President of Iran
• 1960 – Kelley Eskridge, American author and screenwriter
• 1960 – Musalia Mudavadi, Kenyan politician and Former Deputy Prime Minister
• 1960 – Graham Southern, English art dealer and gallery owner
• 1960 – Maurizio Cattelan, Italian sculptor
• 1961 – Billy Collins, Jr., American boxer (d. 1984)
• 1961 – Dan Borislow, American businessman and inventor (d. 2014)
• 1961 – Serena Scott Thomas, English actress and producer
• 1961 – Nancy Travis, American actress and producer
• 1962 – Rob Morrow, American actor
• 1963 – Curtly Ambrose, Antiguan cricketer and bass player
• 1963 – Cecil Fielder, American baseball player and manager
• 1963 – Angus Macfadyen, Scottish actor and screenwriter
• 1963 – Mamoru Samuragochi, Japanese composer
• 1963 – Trevor Steven, English footballer
• 1963 – David J. Wales, British academic and educator
• 1964 – Jorge Drexler, Uruguayan singer-songwriter
• 1964 – Lester Quitzau, Canadian guitarist
• 1965 – Frédéric Beigbeder, French author and critic
• 1965 – Cheryl Hines, American actress
• 1965 – Johanna Vuoksenmaa, Finnish director and screenwriter
• 1966 – Kerrin Lee-Gartner, Canadian skier and journalist
• 1967 – Faith Hill, American singer-songwriter, producer, and actress
• 1967 – Suman Pokhrel, Nepali poet, lyricist and playwright
• 1967 – Tyler Stewart, Canadian drummer
• 1968 – Kevin Buzzard, British mathematician
• 1968 – David Jude Jolicoeur, American rapper, songwriter, and producer (d. 2023)
• 1968 – Ricki Lake, American actress, producer, and talk show host
• 1969 – Anne Burrell, American chef and television host
• 1969 – Jason Christiansen, American baseball player
• 1969 – Curtis Leschyshyn, Canadian ice hockey player and sportscaster
• 1969 – Billy Porter, American actor and singer
• 1970 – Rob Benedict, American actor, screenwriter, and musician
• 1970 – Melissa Ferrick, American singer-songwriter and guitarist
• 1970 – Samantha Power, Irish-American journalist, academic, and diplomat, 28th United States Ambassador to the United Nations
• 1971 – John Crawley, English cricketer and academic
• 1971 – James Lesure, Americana actor
• 1971 – Alfonso Ribeiro, American actor, director, and comedian
• 1971 – Luke Wilson, American actor, director, and screenwriter
• 1972 – Olivia Bonamy, French actress
• 1972 – Liam Gallagher, English singer-songwriter
• 1972 – Jon Kitna, American football player and coach
• 1973 – Vanessa Grigoriadis, American journalist and author
• 1973 – Virginia Ruano Pascual, Spanish tennis player
• 1973 – Oswaldo Sánchez, Mexican footballer
• 1974 – Bryce Drew, American basketball player and coach
• 1974 – Andy Todd, English footballer and manager
• 1975 – Doug Davis, American baseball player
• 1976 – Jonas Bjerre, Danish singer-songwriter and guitarist
• 1976 – Poul Hübertz, Danish footballer and manager
• 1977 – Kārlis Lācis, Latvian pianist and composer
• 1977 – Andre Pärn, Estonian basketball player
• 1977 – Kohei Sato, Japanese wrestler
• 1977 – Brian Tallet, American baseball player
• 1978 – Paulo Costanzo, Canadian actor, director, and producer
• 1978 – Luke Godden, Australian footballer
• 1978 – Doug Howlett, New Zealand rugby player
• 1979 – James Allan, Scottish singer-songwriter and guitarist
• 1979 – Richard Dunne, Irish footballer
• 1979 – Chris Gayle, Jamaican cricketer
• 1979 – Julian Gray, English footballer
• 1979 – Monika Merl, German runner
• 1980 – Nyree Kindred, Welsh swimmer
• 1980 – Tomas Scheckter, South African race car driver
• 1980 – Autumn Reeser, American actress
• 1980 – Kareena Kapoor, Indian actress
• 1981 – Nicole Richie, American actress, fashion designer, and author
• 1981 – Sarah Whatmore, English singer-songwriter
• 1982 – Eduardo Azevedo, Brazilian race car driver
• 1982 – Dominic Perrottet, Australian politician, 46th Premier of New South Wales
• 1982 – Christos Tapoutos, Greek basketball player
• 1982 – Rowan Vine, English footballer
• 1983 – Ndiss Kaba Badji, Senegalese athlete
• 1983 – Fernando Cavenaghi, Argentine footballer
• 1983 – Francesco Dracone, Italian race car driver
• 1983 – Scott Evans, American actor
• 1983 – Anna Favella, Italian actress
• 1983 – Maggie Grace, American actress
• 1983 – Cristian Hidalgo, Spanish footballer
• 1983 – Greg Jennings, American football player
• 1983 – Joseph Mazzello, American actor, director, producer, and screenwriter
• 1983 – Anna Meares, Australian track cyclist
• 1983 – Reggie Nelson, American football player
• 1983 – Rafael Marques Pinto, Brazilian footballer
• 1984 – Dwayne Bowe, American football player
• 1984 – Ahna O'Reilly, American actress
• 1984 – Ben Wildman-Tobriner, American swimmer
• 1984 – Wale, American rapper
• 1985 – Justin Durant, American football player
• 1986 – Faris Badwan, English singer-songwriter
• 1986 – Lindsey Stirling, American violinist and composer
• 1987 – Jimmy Clausen, American football player
• 1987 – Anthony Don, Australian rugby league player
• 1987 – Marcelo Estigarribia, Paraguayan footballer
• 1987 – Ryan Guzman, American actor and model
• 1987 – Murilo Maccari, Brazilian footballer
• 1987 – Ashley Paris, American basketball player
• 1987 – Courtney Paris, American basketball player
• 1987 – Michał Pazdan, Polish footballer
• 1987 – Ivelisse Vélez, Puerto Rican wrestler
• 1988 – Doug Baldwin, American football player
• 1988 – Bilawal Bhutto Zardari, Pakistani politician
• 1989 – Jason Derulo, American singer-songwriter
• 1989 – Sandor Earl, Australian rugby league player
• 1989 – Manny Harris, American basketball player
• 1989 – Emma Watkins, Australian singer and actress
• 1990 – Al-Farouq Aminu, American basketball player
• 1990 – Danny Batth, English footballer
• 1990 – Rob Cross, English darts player
• 1990 – Ivan Dorschner, American-Filipino model and actor
• 1990 – Sam Kasiano, New Zealand rugby league player
• 1990 – Allison Scagliotti, American actress and musician
• 1990 – Christian Serratos, American actress
• 1991 – Anastassia Kovalenko, Estonian motorcycle racer
• 1991 – Carlos Martínez, Dominican baseball player
• 1992 – Kim Jong-dae, South Korean singer-songwriter
• 1992 – Rodrigo Godínez, Mexican footballer
• 1992 – Devyn Marble, American basketball player
• 1993 – Kirsty Gilmour, Scottish badminton player
• 1993 – Kwon Mina, South Korean singer and actress
• 1993 – Ante Rebić, Croatian footballer
• 1994 – Devin Williams, American baseball player
• 1995 – Bruno Caboclo, Brazilian basketball player
• 1998 – Máscara de Bronce, Mexican wrestler
• 1998 – Yainer Díaz, Dominican baseball player
• 1999 – Wang Junkai, Chinese singer
• 1999 – Alexander Isak, Eritrean-Swedish professional footballer

Pre-1600

• 19 BC – Virgil, Roman poet (b. 70 BC)
• 454 – Flavius Aetius, Roman general and politician (b. 396)
• 687 – Pope Conon (b. 630)
• 1026 – Otto-William, Count of Burgundy
• 1217 – Lembitu, Estonian king and military leader
• 1217 – Caupo of Turaida
• 1235 – Andrew II of Hungary (b. 1175)
• 1256 – William of Kilkenny, Lord Chancellor of England
• 1327 – Edward II of England (b. 1284)
• 1397 – Richard FitzAlan, 11th Earl of Arundel, English admiral (b. 1346)
• 1558 – Charles V, Holy Roman Emperor (b. 1500)
• 1576 – Gerolamo Cardano, Italian mathematician, physician, and astrologer (b. 1501)
• 1586 – Antoine Perrenot de Granvelle, French cardinal and diplomat (b. 1517)

1601–1900

• 1629 – Jan Pieterszoon Coen, Governor-General of the Dutch East Indies (b. 1587)
• 1637 – William V, Landgrave of Hesse-Kassel (b. 1602)
• 1643 – Emperor Hong Taiji of China (b. 1592)
• 1709 – Ivan Mazepa, Ukrainian statesman, Hetman of Zaporizhian Host (b. 1639)
• 1719 – Johann Heinrich Acker, German historian and academic (b. 1647)
• 1743 – Jai Singh II, Indian king (b. 1688)
• 1748 – John Balguy, English philosopher and author (b. 1686)
• 1796 – François Séverin Marceau-Desgraviers, French general (b. 1769)
• 1798 – George Read, American lawyer and politician, 3rd Governor of Delaware (b. 1733)
• 1812 – Emanuel Schikaneder, German actor and playwright (b. 1751)
• 1832 – Walter Scott, Scottish novelist, playwright, and poet (b. 1771)
• 1860 – Arthur Schopenhauer, German philosopher and author (b. 1788)
• 1874 – Jean-Baptiste Élie de Beaumont, French geologist and engineer (b. 1798)
• 1880 – Manuel Montt, Chilean scholar and politician, 6th President of Chile (b. 1809)

1901–present

• 1904 – Chief Joseph, American tribal leader (b. 1840)
• 1905 – Nikolay Benardos, Ukrainian inventor (b. 1842)
• 1906 – Samuel Arnold, American conspirator (b. 1838)
• 1926 – Léon Charles Thévenin, French engineer (b. 1857)
• 1933 – Kenji Miyazawa, Japanese author and poet (b. 1896)
• 1937 – Osgood Perkins, American actor (b. 1892)
• 1938 – Ivana Brlić-Mažuranić, Croatian author and poet (b. 1874)
• 1939 – Armand Călinescu, Romanian economist and politician, 39th Prime Minister of Romania (b. 1893)
• 1942 – John Symes, English cricketer (b. 1879)
• 1944 – Alexander Koshetz, Ukrainian choral conductor, arranger, composer (b. 1875)
• 1944 – Artur Phleps, Romanian general (b. 1881)
• 1947 – Harry Carey, American actor, director, producer, and screenwriter (b. 1878)
• 1953 – Necmettin Sadak, Turkish publisher and politician, 10th Turkish Minister of Foreign Affairs (b. 1890)
• 1954 – Mikimoto Kōkichi, Japanese businessman (b. 1858)
• 1956 – Bill Struth, Scottish footballer and manager (b. 1875)
• 1957 – Haakon VII of Norway (b. 1872)
• 1958 – Peter Whitehead, English race car driver (b. 1914)
• 1961 – Ed Oliver, American golfer (b. 1915)
• 1962 – Bo Carter, American singer-songwriter and guitarist (b. 1892)
• 1963 – Paulino Masip, Spanish author, playwright, and screenwriter (b. 1899)
• 1964 – Josef Müller, Croatian entomologist (b. 1880)
• 1966 – Paul Reynaud, French lawyer and politician, 118th Prime Minister of France (b. 1878)
• 1971 – Bernardo Houssay, Argentinian physiologist and physician, Nobel Prize laureate (b. 1887)
• 1972 – Henry de Montherlant, French essayist, novelist, and dramatist (b. 1896)
• 1974 – Walter Brennan, American actor (b. 1894)
• 1974 – Jacqueline Susann, American author and actress (b. 1918)
• 1975 – Bedri Rahmi Eyüboğlu, Turkish painter and poet (b. 1911)
• 1976 – Benjamin Graham, British-American economist, professor, and investor (b. 1894)
• 1976 – Orlando Letelier, Chilean economist and politician, Minister of Foreign Affairs for Chile (b. 1932)
• 1982 – Ivan Bagramyan, Russian general (b. 1897)
• 1983 – Andrew Brewin, Canadian politician (b. 1907)
• 1983 – Bob Donham, American basketball player (b. 1926)
• 1983 – Bada Rajan, Indian mobster (b. unknown)
• 1983 – Birgit Tengroth, Swedish actor (b. 1915)
• 1983 – Willy Trenk-Trebitsch, Austrian actor (b. 1902)
• 1983 – Xavier Zubiri, Basque philosopher (b. 1898)
• 1985 – Gu Long, Chinese author and screenwriter (b. 1937)
• 1987 – Jaco Pastorius, American bass player, composer, and producer (b. 1951)
• 1988 – Glenn Robert Davis, American lieutenant and politician (b. 1914)
• 1989 – Rajini Thiranagama, Sri Lankan physician and academic (b. 1954)
• 1990 – Takis Kanellopoulos, Greek director, producer, and screenwriter (b. 1933)
• 1991 – Gordon Bashford, English engineer (b. 1916)
• 1992 – Tarachand Barjatya, Indian film producer, founded Rajshri Productions (b. 1914)
• 1995 – Rudy Perpich, American dentist and politician, 34th Governor of Minnesota (b. 1928)
• 1998 – Florence Griffith Joyner, American sprinter (b. 1959)
• 2000 – Jacques Flynn, Canadian lawyer and politician, 35th Canadian Minister of Justice (b. 1915)
• 2000 – Leonid Rogozov, Russian physician and surgeon (b. 1934)
• 2002 – Robert L. Forward, American physicist and science fiction author (b. 1932)
• 2004 – Bob Mason, English actor and screenwriter (b. 1952)
• 2006 – Tasos Athanasiadis, Greek author (b. 1913)
• 2007 – Hallgeir Brenden, Norwegian skier (b. 1929)
• 2007 – Alice Ghostley, American actress (b. 1923)
• 2007 – Rex Humbard, American evangelist and television host (b. 1919)
• 2009 – Robert Ginty, American actor, director, and screenwriter (b. 1948)
• 2011 – John Du Cann, English guitarist (b. 1946)
• 2011 – Jun Henmi, Japanese author and poet (b. 1939)
• 2011 – Pamela Ann Rymer, American lawyer and judge (b. 1941)
• 2012 – José Curbelo, Cuban-American pianist and manager (b. 1917)
• 2012 – Yehuda Elkana, Israeli historian and philosopher (b. 1934)
• 2012 – Sven Hassel, Danish-German soldier and author (b. 1917)
• 2012 – Bill King, English commander, sailor, and author (b. 1910)
• 2012 – Tom Umphlett, American baseball player and manager (b. 1930)
• 2013 – Kofi Awoonor, Ghanaian author, poet, and diplomat (b. 1935)
• 2013 – Michel Brault, Canadian director, producer, and screenwriter (b. 1928)
• 2013 – Harl H. Haas, Jr., American lawyer, jurist, and politician (b. 1932)
• 2013 – Walter Wallmann, German lawyer and politician, Minister-President of Hesse (b. 1932)
• 2013 – Ko Wierenga, Dutch lawyer and politician (b. 1933)
• 2014 – Michael Harari, Israeli intelligence officer (b. 1927)
• 2014 – Caldwell Jones, American basketball player and coach (b. 1950)
• 2014 – Sheldon Patinkin, American director and playwright (b. 1935)
• 2015 – Yoram Gross, Polish-Australian director and producer (b. 1926)
• 2015 – Ray Warleigh, Australian-English saxophonist and flute player (b. 1938)
• 2015 – Richard Williamson, American footballer and coach (b. 1941)
• 2018 – Trần Đại Quang, President of Vietnam (b. 1956)
• 2018 – Vitaliy Masol, Ukrainian Former Prime Minister (b. 1928)
• 2020 – Arthur Ashkin, American scientist and Nobel laureate (b. 1922)
• 2021 – Willie Garson, American actor (b. 1964)
• 2022 – Raju Srivastav, Indian comedian, actor and politician (b. 1963)
• 2023 – Walewska Oliveira, Brazilian volleyball player and Olympic champion (b. 1979)

• Autumnal equinox observances in the Northern Hemisphere, vernal equinox observances in the Southern Hemisphere (see September 22):
  • Spring Day (Argentina)

• Christian feast day:
  • Ephigenia of Ethiopia
  • Laurent-Joseph-Marius Imbert (one of the Korean Martyrs)
  • Matthew the Evangelist (Western Church)
  • Nativity of the Theotokos (Eastern Orthodox Church, Julian calendar)
  • September 21 (Eastern Orthodox liturgics)
• Arbor Day (Brazil)
• Commemoration of the Declaration of Martial Law (Philippines)
• Customs Service Day (Poland)
• Founder's Day and National Volunteer Day (Ghana)
• Independence Day, celebrates the independence of Armenia from the Soviet Union in 1991.
• Independence Day, celebrates the independence of Belize from the United Kingdom in 1981.
• Independence Day, celebrates the independence of Malta from the United Kingdom in 1964.
• International Day of Peace (International)
• Student's Day (Bolivia)
• Victory over the Golden Horde in the Battle of Kulikovo (Russia)

• In the popular 1978 song "September" by Earth, Wind & Fire, the date is mentioned in the lyric "Do you remember the 21st night of September?" Reference to this date has gained popularity due to the song's spread as an internet meme.

• "On This Day". BBC.
• The New York Times: On This Day
• "Historical Events on September 21". OnThisDay.com.