October 20 is the 293rd day of the year (294th in leap years) in the Gregorian calendar. There are 72 days remaining until the end of the year.
Up to 1950
- 1548 - The city of La Paz, Bolivia, is founded.
- 1708 - The new Saint Paul's Cathedral in London, designed by Christopher Wren, is completed.
- 1714 - George I of Great Britain and Ireland is crowned.
- 1720 - Caribbean pirate Calico Jack is captured by the Royal Navy.
- 1728 - The Great Fire of Copenhagen break out, and lasts for three days.
- 1740 – Maria Theresa takes the throne of Austria. France, Prussia, Bavaria, and Saxony refuse to honour the Pragmatic Sanction and the War of the Austrian Succession begins.
- 1803 – United States Senate ratifies the Louisiana Purchase.
- 1818 - The Convention of 1818 is signed between the United States and United Kingdom. Among other things, it settles most of the Canada-United States border to run along the 49th parallel.
- 1827 – Battle of Navarino – a combined Turkish and Egyptian armada is destroyed by an allied British, French, and Russian naval force in the port of Navarino in Pylos, Greece. The most important result of this battle is the end of the Greek Liberation War and the affirmation of independence of modern Greece.
- 1831 - First day of trading on the Madrid Stock Exchange.
- 1883 – Peru and Chile signed the Treaty of Ancón, by which the Tarapacá province was ceded to the latter, bringing an end to Peru's involvement in the War of the Pacific.
- 1904 - Chile and Bolivia sign the Treaty of Peace and Friendship.
- 1910 - The hull of the ship RMS Olympic is launched in Belfast.
- 1914 - World War I: The First Battle of Flanders begins.
- 1935 – The Long March ends in China.
- 1943 - Cargo vessel Sinfra is attacked by allied aircraft at Suda Bay, Crete and sunk. 2,098 Italian POWs drown.
- 1944 – The Soviet army captures Belgrade, the capital of Yugoslavia
- 1944 – Liquid natural gas leaks from storange tanks in Cleveland, Ohio, then explodes; the explosion and resulting fire level 30 blocks and kill 130.
- 1947 – The House Un-American Activities Committee begins its investigation into Communist infiltration of Hollywood, resulting in a blacklist that prevents some from working in the industry for years.
- 1948 - A KLM Lockheed L-049 Constellation airliner crashes at Glasgow Prestwick Airport in Scotland, killing all 40 people on board.
From 1951
- 1952 - In then-British Kenya, leaders of the Mau-Mau uprising are arrested, including Jomo Kenyatta.
- 1968 – Former First Lady Jacqueline Kennedy marries Greek shipping tycoon Aristotle Onassis.
- 1970 - Siad Barre declares Somalia a socialist state.
- 1971 - West German Chancellor Willy Brandt wins the Nobel Peace Prize.
- 1971 – The Nepal stock exchange collapses.
- 1973 – The Saturday Night Massacre: President Nixon fires Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus after they refuse to fire Watergate prosecutor Archibald Cox, who is finally fired by Robert Bork.
- 1973 – The Sydney Opera House opens.
- 1973 – The Six Million Dollar Man premieres on ABC.
- 1976 - The ferry George Prince is struck by a ship on the Mississippi River in Louisiana, killing 78 people. 18 survive.
- 1977 – A plane carrying Lynyrd Skynyrd crashes in Mississippi, killing several band members, including lead singer Ronnie Van Zant and guitarist Steve Gaines.
- 1982 – St. Louis Cardinals defeat Milwaukee Brewers 6-3 to win 9th World Series Championship.
- 1986 – Yitzhak Shamir begins his second office term as Israel's prime minister.
- 1991 – A magnitude 6.8 earthquake in northern India kills around 1,000 people.
- 1991 – The Oakland Hills firestorm kills 25 and destroys 3469 homes and apartments, causing more than $2 billion in damage.
- 1995 - NATO Secretary-General Willy Claes resigns.
- 1999 – Abdurrahman Wahid is elected President of Indonesia.
- 2004 - Susilo Bambang Yudhoyono becomes President of Indonesia.
- 2007 – South Africa wins the Rugby World Cup, defeating England in the final.
- 2011 – 2011 Libyan civil war: Forces loyal to the National Transitional Council take the city of Sirte, the last remaining pro-Gaddafi stronghold. Subsequently, Colonel Muammar al-Gaddafi is captured and killed.
- 2013 - Luxembourg holds an early election after long-serving Prime Minister Jean-Claude Juncker was involved in a spy scandal.
- 2014 - Joko Widodo becomes President of Indonesia.
- 2018 - Around 700,000 people march against Brexit (and for a second referendum on the issue) in London, in the biggest such gathering in the United Kingdom since 2003.
- 2018 - Donald Trump decides to pull the United States out of the Intermediate-Range Nuclear Forces Treaty with Russia.
Up to 1900
- 1435 - Andrea Della Robbia, Italian sculptor (died 1525)
- 1463 – Alessandro Achillini, Italian philosopher (died 1512)
- 1469 – Guru Nanak Dev ji, The Founder of the Sikh religion.
- 1496 - Claude, Duke of Guise, French general (d. 1550)
- 1616 - Thomas Bartholin, Danish physician, mathematician and theologian (died 1680)
- 1632 – Sir Christopher Wren, English architect (died 1723)
- 1677 – Stanislaw I Leszczynski, King of Poland (died 1766)
- 1711 - Timothy Ruggles, American politician (died 1795)
- 1759 – Chauncey Goodrich, U.S. Senator from Connecticut (died 1815)
- 1780 - Pauline Bonaparte, French sister of Napoleon Bonaparte (died 1825)
- 1784 – Henry Temple, 3rd Viscount Palmerston, Prime Minister of the United Kingdom (died 1865)
- 1785 - George Ormerod, British historian and antiquarian (died 1873)
- 1801 - Melchior Berri, Swiss architect (died 1854)
- 1808 – Karl Andree, German geographer (died 1875)
- 1819 – The Báb, prophet founder of the Bábí Faith, precursor to the Bahá'í Faith (died 1850)
- 1819 - Carl Mikuli, Polish pianist (died 1897)
- 1822 – Thomas Hughes, novelist (died 1896)
- 1825 - Daniel Sickles, American politician, soldier and diplomat (died 1914)
- 1832 - Constantin Lipsius, German architect (died 1894)
- 1836 - Daniel Owen, Welsh novelist (died 1895)
- 1847 - Oscar Swahn, Swedish archer (died 1927)
- 1854 – Arthur Rimbaud, French poet (died 1891)
- 1854 - James F. Hinkle, 6th Governor of New Mexico (died 1951)
- 1858 – John Burns, English politician (died 1943)
- 1859 – John Dewey, American philosopher (died 1952)
- 1864 - James F. Hinkle, American politician, 6th Governor of New Mexico (died 1951)
- 1866 - Kazimierz Twardowski, Polish philosopher (died 1938)
- 1869 - Robin Welsh, Scottish curler and rugby union player (died 1934)
- 1873 - Nellie McClung, Canadian politician and activist (died 1951)
- 1874 – Charles Ives, American composer (died 1954)
- 1876 - Alexandre Pharamond, French rugby player (died 1953)
- 1882 – Bela Lugosi, Hungarian-American actor (died 1956)
- 1882 – Margaret Dumont, American actress (died 1965)
- 1887 - Prince Yasuhiko Asaka, Japanese diplomat (died 1981)
- 1890 – Jelly Roll Morton, American composer, musician (died 1941)
- 1891 – Jomo Kenyatta, President of Kenya (died 1978)
- 1891 – James Chadwick, English physicist (died 1974)
- 1893 – Charley Chase, early movie comedian (died 1940)
- 1894 - Olive Thomas, American actress and model (died 1920)
- 1895 - Rex Ingram, American actor (died 1969)
- 1897 – Crown Prince Eun of Korea (died 1970)
- 1900 – Wayne Morse, Senator from Oregon (died 1974)
1901 – 1950
- 1901 - Adelaide Hall, American-British pianist, composer and bandleader (died 1993)
- 1904 – Anna Neagle, English actress (died 1986)
- 1904 – Tommy Douglas, Scottish-Canadian politician, founder of public healthcare in Canada (died 1986)
- 1905 – Frederic Dannay (Ellery Queen), mystery novelist (died 1982)
- 1907 – Arlene Francis, television personality (died 2001)
- 1909 - Carla Laemmle, American actress (died 2014)
- 1910 - Bob Sheppard, American sportscaster (died 2010)
- 1913 – Grandpa Jones, American country music performer (died 1998)
- 1917 - Stéphane Hessel, French diplomat and activist (died 2013)
- 1917 - Jean-Pierre Melville, French director and screenwriter (died 1973)
- 1918 – Robert Lochner, journalist, creator of Kennedy's "ish been oin bear-lee-ner" (died 2003)
- 1920 – Janet Jagan, American-born President of Guyana (died 2009)
- 1920 - Nick Cardy, American illustrator (died 2013)
- 1920 - Siddhartha Shankar Ray, Indian politician, Chief Minister of West Bengal (died 2010)
- 1923 - Robert Craft, American conductor (died 2015)
- 1923 – Otfried Preussler, German children's writer (died 2013)
- 1923 – Herschel Bernardi, actor (died 1986)
- 1924 - Robert Peters, American poet, scholar, playwright, editor and actor (died 2014)
- 1925 – Art Buchwald, newspaper columnist
- 1925 - Roger Hanin, French director and actor (died 2015)
- 1926 - Edward Douglas-Scott-Montagu, 3rd Baron Montagu of Beaulieu, English politician (died 2015)
- 1927 – Joyce Brothers, American psychologist, television personality (died 2013)
- 1928 - Li Peng, Chinese politician (died 2019)
- 1931 – Mickey Mantle, American baseball player (died 1995)
- 1931 - Richard Caliguiri, 54th Mayor of Pittsburgh (died 1988)
- 1931 - Zeke Bratkowski, American football player (died 2019)
- 1932 – Rosey Brown, American Pro Football Hall of Famer (died 2004)
- 1932 – William Christopher, American actor (died 2016)
- 1934 – Empress Michiko of Japan
- 1934 - Taku Mayumura, Japanese science fiction novelist (died 2019)
- 1934 – Eddie Harris, American jazz saxophonist (died 1996)
- 1934 – Timothy West, English actor
- 1934 - Bill Chase, American trumpeter (died 1974)
- 1935 - Roy Bailey, English folk singer and guitarist (died 2018)
- 1935 – Jerry Orbach, American actor (Law & Order) (died 2004)
- 1936 - Bobby Seale, American activist
- 1937 – Juan Marichal, Dominican baseball player
- 1937 - Wanda Jackson, American singer
- 1938 - Kathy Kirby, English singer (died 2011)
- 1942 – Christiane Nüsslein-Volhard, German biologist
- 1945 – Romeo Benetti, Italian footballer
- 1946 – Elfriede Jelinek, Austrian writer, won the 2004 Nobel Prize in Literature
- 1946 - Chris Woodhead, English civil servant and academic (died 2015)
- 1947 - Tom Smith, American politician (died 2015)
- 1948 - Sandra Dickinson, British actress
- 1949 – Valeri Borzov, Ukrainian athlete
- 1950 – Tom Petty, American musician (died 2017)
- 1950 - Chris Cannon, American politician
1951 – 1975
- 1951 – Claudio Ranieri, Italian footballer and manager
- 1951 - Alma Muriel, Mexican actress (died 2014)
- 1951 – Al Greenwood, American rock musician
- 1953 – Bill Nunn, American actor
- 1955 - Sheldon Whitehouse, United States Senator
- 1955 – Aaron Pryor, world boxing champion
- 1955 - Thomas Newman, American composer and conductor
- 1956 – Danny Boyle, British movie director
- 1957 - Jane Bonham-Carter, Baroness Bonham-Carter of Yanbury, British politician
- 1957 - Hilda Solis, American politician
- 1958 – Viggo Mortensen, American actor
- 1958 – Ivo Pogorelic, Croatian pianist
- 1959 - Eriko Asai, Japanese long-distance runner
- 1959 - Akif Pirinçci, Turkish-German author
- 1960 – Konstantin Aseev, chess player (died 2004)
- 1960 - Lepa Brena, Bosnian singer and actress
- 1961 – Ian Rush, Welsh footballer
- 1961 - Kate Mosse, English writer
- 1961 - Michio Tomizawa, Japanese voice actress
- 1962 - David M. Evans, American director and screenwriter
- 1963 - Nikos Tsiantakis, Greek footballer
- 1963 – Julie Payette, Canadian astronaut and Governor General of Canada
- 1964 - Kamala Harris, American lawyer and politician
- 1965 – Billy Zabka, American actor
- 1966 – Stefan Raab, German entertainer
- 1966 – Allan Donald, South African cricketer
- 1966 – Abu Musab al-Zarqawi, Jordanian militant and al-Qaeda member (died 2006)
- 1966 - Patrick Volkerding, American computer scientist and engineer
- 1967 – Monica Ali, British writer
- 1969 – Juan Gonzalez, baseball player
- 1970 - Nikky Smedley, British actress
- 1971 - Karl Collins, British actor
- 1971 – Dannii Minogue, Australian singer
- 1971 – Snoop Dogg, American rapper
- 1971 - Eddie Jones, American basketball player
- 1972 – Will Greenwood, English rugby player
- 1972 - Brian Schatz, American politician, United States Senator for Hawaii
From 1976
- 1976 – Nicola Legrottaglie, Italian footballer
- 1976 - Dan Fogler, American actor and director
- 1977 – Elena Berezhnaya, figure skating star
- 1978 – Paul Wilson, Scottish musician (Snow Patrol)
- 1978 – Virender Sehwag, Indian cricketer
- 1979 – John Krasinski, American actor
- 1981 – Dimitrios Papadopoulos, Greek footballer
- 1981 - Francisco Rodríguez, Mexican footballer
- 1981 – Willis McGahee, American football player
- 1983 - Michel Vorm, Dutch footballer
- 1984 – Andrew Trimble, Northern Irish rugby player
- 1984 - Mitch Lucker, American singer-songwriter (died 2012)
- 1985 – Dominic McGuire, American basketball player
- 1986 – Priyanka Sharma, Indian actress
- 1988 – Risa Niigaki, Japanese singer (Morning Musume)
- 1988 - Candice Swanepoel, South African model
- 1989 - Jess Glynne, English singer-songwriter
- 1989 - Yanina Wickmayer, Belgian tennis player
- 1992 - Ksenia Semenov, Russian gymnast
- 1994 – Morgan Featherstone, Australian model
- 1995 - Zhenwei Wang, Chinese actor and martial artist
Up to 1950
- 460 - Aelia Eudocia, Byzantine Empress
- 1139 - Henry X, Duke of Bavaria
- 1631 – Michael Maestlin, German astronomer and mathematician (b. 1550)
- 1640 – John Ball, English Puritan clergyman (b. 1585)
- 1652 - Antonio Coello, Spanish poet and playwright (b. 1611)
- 1713 - Archibald Pitcairne, Scottish physician (b. 1652)
- 1740 – Charles VI, Holy Roman Emperor (b. 1685)
- 1842 - Grace Darling, English heroine (b. 1815)
- 1896 – Felix Tisserand, French astronomer (b. 1845)
- 1900 – Naim Frasheri, Albanian poet (b. 1846)
- 1907 – Said Pasha Kurd, Kurdish statesman (b. 1834)
- 1910 - David B. Hill, 29th Governor of New York (b. 1843)
- 1926 - Eugene V. Debs, American politician (b. 1855)
- 1935 – Arthur Henderson, Scottish politician (b. 1863)
- 1936 – Anne Sullivan, American teacher (b. 1866)
- 1940 - Gunnar Asplund, Swedish architect (b. 1885)
- 1946 - Piero Campelli, Italian footballer (b. 1893)
- 1950 - Henry L. Stimson, American statesman, lawyer and politician (b. 1867)
1951 – 2000
- 1957 - Michalis Dorizas, Greek javelin thrower (b. 1890)
- 1964 – Herbert Hoover, 31st President of the United States (b. 1874)
- 1966 - Harry F. Byrd, Governor of Virginia (b. 1887)
- 1967 – Shigeru Yoshida, Prime Minister of Japan (b. 1878)
- 1968 – Bud Flanagan, British wartime entertainer (b. 1896)
- 1972 - Harlow Shapley, American astronomer (b. 1885)
- 1977 – Cassie Gaines, American musician (Lynyrd Skynyrd) (b. 1948) (plane crash)
- 1977 – Steve Gaines, American musician (Lynyrd Skynyrd) (b. 1949) (plane crash)
- 1977 – Ronnie Van Zant, American musician (Lynyrd Skynyrd) (b. 1948) (plane crash)
- 1978 – Gunnar Nilsson, Swedish racing driver (b. 1948)
- 1984 – Paul Dirac, English physicist (b. 1902)
- 1984 – Carl Ferdinand Cori, Czech doctor, won the 1947 Nobel Prize in Physiology or Medicine (b. 1896)
- 1987 – Andrey Kolmogorov, Russian mathematician (b. 1903)
- 1989 - Anthony Quayle, English actor (b. 1913)
- 1994 – Sergei Bondarchuk, Russian actor and director (b. 1920)
- 1994 – Burt Lancaster, American actor (b. 1913)
- 1999 – Jack Lynch, Irish Taoiseach (b. 1917)
From 2001
- 2005 - Shirley Horn, American jazz pianist (b. 1934)
- 2005 - André van der Louw, Dutch politician, Mayor of Rotterdam (b. 1933)
- 2006 - Maxi Herber, German figure skater (b. 1920)
- 2008 – Soeur Emmanuelle, French-Belgian nun and humanitarian (b. 1908)
- 2010 – Farooq Leghari, President of Pakistan (b. 1940)
- 2010 – Bob Guccione, American publisher (b. 1930)
- 2011 – Muammar al-Gaddafi, colonel and military ruler of Libya (b. 1942)
- 2012 - E. Donnall Thomas, American physician and Nobel Prize winner (b. 1920)
- 2012 - Paul Kurtz, American academic (b. 1925)
- 2013 - Jovanka Broz, former First Lady of Yugoslavia (b. 1924)
- 2013 - Lawrence Klein, American economist (b. 1920)
- 2014 - Ox Baker, American wrestler and actor (b. 1938)
- 2014 - Oscar de la Renta, Dominican Republic fashion designer (b. 1932)
- 2014 - René Burri, Swiss photographer (b. 1933)
- 2014 - Pavle Merku, Slovenian composer (b. 1927)
- 2014 - Christophe de Margerie, French businessman (b. 1951)
- 2015 - Michael Meacher, English politician (b. 1939)
- 2015 - Cory Wells, American singer (b. 1941)
- 2017 - Federico Luppi, Argentine-Spanish actor (b. 1936)
- 2017 - Stan Kowalski, American professional wrestler (b. 1926)
- 2018 - Wim Kok, Prime Minister of the Netherlands (b. 1938)
- 2018 - Zheng Xiaosong, Chinese politician (b. 1959)
- 2019 - Eric Cooper, American baseball umpire (b. 1966)
- 2019 - Thomas D'Alesandro III, American politician (b. 1929)
- 2019 - Huang Yong Ping, Chinese-French avant-garde artist (b. 1954)
- 2019 - Aquilino Pimentel Jr., Filipino politician (b. 1933)
- 2023 - Hiba Abu Nada, Palestinian poet and novelist[1]