1920 was a leap year starting on Thursday in the Gregorian calendar.  It was the first year of the 1920s.

Events 
 The King of Spain blesses the Real Madrid football team.
 August Krogh, Danish zoologist, won the 1920 Nobel Prize in Physiology or Medicine

Births 
 January 9 - Clive Dunn, British actor, comedian, and singer (d. 2012)
 January 20 – DeForest Kelley, American actor (d. 1999)
 February 26 – Tony Randall, American actor (d. 2004)
 May 18 – John Paul II, Polish-born Pope (d. 2005)
 June 10 – Ruth Graham, American poet, wife of Billy Graham (d. 2007)
 August 18 - Shelley Winters, American actress (d. 2006)
 August 22 – Ray Bradbury, American writer (d. 2012)
 September 23 - Mickey Rooney, American actor (d. 2014)
 November 8 – Esther Rolle, American actress, known for role in Good Times and Maude (d.1998)
 November 21 - Stan Musial, American baseball player (d. 2013)

Deaths 
 January 2 – Paul Adam, French writer (b. 1862)
 January 3 – Zygmunt Janiszewski, Polish mathematician (b. 1888)
 January 4 – Benito Pérez Galdós, Spanish novelist (b. 1843)
 January 6 – Hieronymus Georg Zeuthen, Danish mathematician (b. 1839)
 January 7 – Edmund Barton, Prime Minister of Australia (b. 1849)
 January 18 – Giovanni Capurro, Italian poet (b. 1825)
 January 24 – William Percy French, Irish songwriter and entertainer (b. 1854)
 January 24 – Amedeo Modigliani, Italian painter and sculptor (tuberculosis) (b. 1884)
 January 24 – William Plunket, 5th Baron Plunket, British diplomat and administrator (b. 1864)
 January 26 – Jeanne Hébuterne, French artist, model, and common-law wife of Amedeo Modigliani (suicide) (b. 1898)
 February 2 – Field E. Kindley, American World War I aviator (b. 1896)
 February 3 – Frank Brown, Governor of Maryland (b. 1846)
 February 6 – Augustus F. Goodridge, Canadian merchant and politician (b. 1839)
 February 7 – Aleksandr Kolchak, Russian naval commander (b. 1874)
 February 15 – Joseph Burton Sumner, founder of Sumner, Mississippi (b. 1837)
 February 20 – Joseph J. Fern, Mayor of Honolulu (b. 1872)
 February 20 – Robert Peary, American Arctic explorer (b. 1856)
 February 27 – William Sherman Jennings, Governor of Florida (b. 1863)
 March 1 – John H. Bankhead, U.S. Senator from Alabama (b. 1842)
 March 1 – William A. Stone, Governor of Pennsylvania (b. 1846)
 March 1 – Joseph Trumpeldor, Russian Zionist (b. 1880)
 March 4 – Roswell P. Bishop, U.S. Congressman from Michigan (b. 1843)
 March 11 – Julio Garavito Armero, Colombian astronomer (b. 1865)
 March 13 – Charles Lapworth, English geologist (b. 1842)
 March 26 – William Chester Minor, American surgeon (b. 1834)
 March 26 – Mary Augusta Ward, Tasmanian novelist (b. 1851)
 March 31 – Paul Bachmann, German mathematician (b. 1837)
 March 31 – Edwin Warfield, Governor of Maryland (b. 1848)
 April 8 – John Brashear, American astronomer (b. 1840)
 April 8 – Charles Tomlinson Griffes, American composer (b. 1884)
 April 9 – Moritz Cantor, German historian of mathematics (b. 1829)
 April 21 – Maria L. Sanford, American educator (b. 1836)
 April 26 – Srinivasa Ramanujan, Indian mathematician (b. 1887)
 May 1 – Princess Margaret of Connaught, Crown Princess of Sweden (b. 1882)
 May 9 – Agnes Macdonald, wife of John A. Macdonald, Prime Minister of Canada (b. 1836)
 May 11 – James Colosimo, Italian-born gangster (b. 1877)
 May 11 – William Dean Howells, American writer (b. 1837)
 May 16 – Levi P. Morton, Vice President of the United States (b. 1824)
 May 21 – Venustiano Carranza, President of Mexico (b. 1859)
 May 21 – Eleanor H. Porter, American novelist (b. 1868)
 May 23 – Svetozar Borojevic, Austro-Hungarian field marshal (b. 1856)
 May 30 – George Ernest Morrison, Australian adventurer (b. 1862)
 June 5 – Rhoda Broughton, Welsh writer (b. 1840)
 June 5 – Julia A. Moore, American poet (b. 1847)
 June 6 – James Dunsmuir, Canadian politician (b. 1851)
 June 13 – Essad Pasha, Prime Minister of Albania (b. 1863)
 June 14 – Gabrielle Réjane, French actress (b. 1856)
 June 14 – Max Weber, German political economist (b. 1864)
 June 18 – Jewett W. Adams, Governor of Nevada (b. 1835)
 June 18 – John Macoun, Irish born naturalist (b. 1831)
 June 20 – Marie Adolphe Carnot, French chemist, mining engineer, and politician (b. 1839)
 June 20 – John Grigg, New Zealand astronomer (b. 1838)
 June 27 – Adolphe Basile Routhier, Canadian poet (b. 1839)
 July 1 – Delfim Moreira, President of Brazil (b. 1868)
 July 10 – John Fisher, 1st Baron Fisher, British admiral (b. 1841)
 July 11 – Empress Eugénie of France (b. 1826)
 July 14 – Albert Keller, German painter (b. 1844)
 July 22 – William Kissam Vanderbilt, American heir (b. 1849)
 August 1 – Frank Hanly, Governor of Indiana (b. 1863)
 August 1 – Bal Gangadhar Tilak, Indian nationalist (b. 1856)
 August 2 – Ormer Locklear, American pilot (b. 1891)
 August 9 – Samuel Griffith, Australian politician and judge (b. 1845)
 August 10 – Adam Politzer, Austrian otologist (b. 1835)
 August 12 – Hermann Struve, Russian-born astronomer (b. 1854)
 August 16 – Henry Daglish, Premier of Australia (b. 1866)
 August 16 – Joseph Norman Lockyer, English astronomer (b. 1836)
 August 17 – Ray Chapman, baseball player (b. 1891)
 August 22 – Anders Zorn, Swedish painter (b. 1860)
 August 26 – James Wilson, Scottish-born American politician (b. 1835)
 August 31 – Wilhelm Wundt, German physiologist and psychologist (b. 1832)
 September 7 – Simon-Napoléon Parent, Premier of Quebec (b. 1855)
 September 10 – Olive Thomas, American actress (b. 1894)
 September 18 – Robert Beaven, Canadian politician (b. 1836)
 September 24 – Peter Carl Fabergé, Russian jeweler (b. 1846)
 September 25 – Jacob Schiff, German-born banker and philanthropist (b. 1847)
 September 30 – William Wilfred Sullivan, Canadian journalist, politician, and jurist (b. 1843)
 October 2 – Winthrop M. Crane, Governor of Massachusetts and Senator (b. 1853)
 October 10 – Hudson Stuck, English mountaineer (b. 1865)
 October 19 – John Reed, American journalist (b. 1887)
 October 20 – Max Bruch, German composer (b. 1838)
 October 24 – Grand Duchess Marie Alexandrovna of Russia (b. 1853)
 November 4 – Ludwig Struve, Russian astronomer (b. 1858)
 November 13 – Luc-Olivier Merson, French painter and illustrator (b. 1846)
 November 23 – George Callaghan, British admiral (b. 1852)
 November 25 – Gaston Chevrolet, Swiss-born automobile race driver and manufacturer (b. 1892)
 November 30 – Eugene W. Chafin, American politician (b. 1852)
 December 3 – William de Wiveleslie Abney, English astronomer and photographer (b. 1843)
 December 11 – Olive Schreiner, South African writer (b. 1855)
 December 12 – Edward Gawler Prior, Canadian mining engineer and politician (b. 1854)
 December 14 – George Gipp, American football player (b. 1895)

Art, music, theatre, literature 
 The Cabinet of Doctor Caligari is released.