April 20

Pre-1600

• 1303 – The Sapienza University of Rome is instituted by a bull of Pope Boniface VIII.

1601–1900

• 1653 – Oliver Cromwell dissolves England's Rump Parliament.
• 1657 – English Admiral Robert Blake destroys a Spanish silver fleet, under heavy fire from the shore, at the Battle of Santa Cruz de Tenerife.
• 1657 – Freedom of religion is granted to the Jews of New Amsterdam (later New York City).
• 1752 – Start of Konbaung–Hanthawaddy War, a new phase in the Burmese Civil War (1740–57).
• 1770 – The Georgian king, Erekle II, abandoned by his Russian ally Count Totleben, wins a victory over Ottoman forces at Aspindza.
• 1775 – American Revolutionary War: The Siege of Boston begins, following the battles at Lexington and Concord.
• 1789 – George Washington arrives at Grays Ferry, Philadelphia, while en route to Manhattan for his inauguration.
• 1792 – France declares war against the "King of Hungary and Bohemia", the beginning of the French Revolutionary Wars.
• 1800 – The Septinsular Republic is established.
• 1809 – Two Austrian army corps in Bavaria are defeated by a First French Empire army led by Napoleon at the Battle of Abensberg on the second day of a four-day campaign that ended in a French victory.
• 1828 – René Caillié becomes the second non-Muslim to enter Timbuktu, following Major Gordon Laing. He would also be the first to return alive.
• 1836 – U.S. Congress passes an act creating the Wisconsin Territory.
• 1859 – Daniel E. Sickles, a New York Congressman, is acquitted of the murder of Philip Barton Key on grounds of temporary insanity. The case marked the first successful use of the "temporary insanity" legal defense.
• 1861 – American Civil War: Robert E. Lee resigns his commission in the United States Army in order to command the forces of the state of Virginia.
• 1861 – Thaddeus S. C. Lowe, attempting to display the value of balloons, makes record journey, flying 900 miles from Cincinnati to South Carolina.
• 1862 – Louis Pasteur and Claude Bernard complete the experiment disproving the theory of spontaneous generation.
• 1865 – Astronomer Angelo Secchi demonstrates the Secchi disk, which measures water clarity, aboard Pope Pius IX's yacht, the L'Immaculata Concezion.
• 1876 – The April Uprising begins. Its suppression shocks European opinion, and Bulgarian independence becomes a condition for ending the Russo-Turkish War.
• 1884 – Pope Leo XIII publishes the encyclical Humanum genus, condemning Freemasonry.
• 1898 – U.S. President William McKinley signs a joint resolution to Congress for declaration of war against Spain, beginning the Spanish–American War.

1901–present

• 1902 – Pierre and Marie Curie refine radium chloride.
• 1908 – Opening day of competition in the New South Wales Rugby League.
• 1914 – Nineteen men, women, and children participating in a strike are killed in the Ludlow Massacre during the Colorado Coalfield War.
• 1918 – Manfred von Richthofen, a.k.a. The Red Baron, shoots down his 79th and 80th victims, his final victories before his death the following day.
• 1922 – The Soviet government creates South Ossetian Autonomous Oblast within Georgian SSR.
• 1945 – World War II: U.S. troops capture Leipzig, Germany, only to later cede the city to the Soviet Union.
• 1945 – World War II: Führerbunker: On his 56th birthday Adolf Hitler makes his last trip to the surface to award Iron Crosses to boy soldiers of the Hitler Youth.
• 1945 – Twenty Jewish children used in medical experiments at Neuengamme are killed in the basement of the Bullenhuser Damm school.
• 1946 – The League of Nations officially dissolves, giving most of its power to the United Nations.
• 1961 – Cold War: Failure of the Bay of Pigs Invasion of US-backed Cuban exiles against Cuba.
• 1968 – English politician Enoch Powell makes his controversial "Rivers of Blood" speech.
• 1968 – South African Airways Flight 228 crashes near the Hosea Kutako International Airport in South West Africa (now Namibia), killing 123 people.
• 1972 – Apollo program: Apollo 16 Lunar Module, commanded by John Young and piloted by Charles Duke, lands on the Moon.
• 1998 – Air France Flight 422 crashes after taking off from El Dorado International Airport in Bogotá, Colombia, killing all 53 people on board.
• 1999 – Columbine High School massacre: Eric Harris and Dylan Klebold kill 13 people and injure 24 others before committing suicide at Columbine High School in Columbine, Colorado.
• 2004 - The Nicoll Highway in Singapore collapsed, killing four workers.
• 2007 – Johnson Space Center shooting: William Phillips barricades himself with a handgun in NASA's Johnson Space Center in Houston, Texas before killing a male hostage and himself.
• 2008 – Danica Patrick wins the Indy Japan 300 becoming the first female driver in history to win an Indy car race.
• 2010 – The Deepwater Horizon drilling rig explodes in the Gulf of Mexico, killing eleven workers and beginning an oil spill that would last six months.
• 2012 – One hundred twenty-seven people are killed when a plane crashes in a residential area near the Benazir Bhutto International Airport near Islamabad, Pakistan.
• 2013 – A 6.6-magnitude earthquake strikes Lushan County, Ya'an, in China's Sichuan province, killing at least 193 people and injuring thousands.
• 2015 – Ten people are killed in a bomb attack on a convoy carrying food supplies to a United Nations compound in Garowe in the Somali region of Puntland.
• 2020 – For the first time in history, oil prices drop below zero, an effect of the 2020 Russia-Saudi Arabia oil price war.
• 2021 – State of Minnesota v. Derek Michael Chauvin: Derek Chauvin is found guilty of all charges in the murder of George Floyd by the Fourth Judicial District Court of Minnesota.
• 2023 – SpaceX's Starship rocket, the largest and most powerful rocket ever built, launches for the first time. It explodes 4 minutes into flight.

Pre-1600

• 1494 – Johannes Agricola, German theologian and reformer (d. 1566)
• 1544 – Renata of Lorraine, Duchess consort of Bavaria (d. 1602)
• 1586 – Rose of Lima, Peruvian mystic and saint (d. 1617)

1601–1900

• 1633 – Emperor Go-Kōmyō of Japan (d. 1654)
• 1646 – Charles Plumier, French botanist and author (d. 1704)
• 1650 – William Bedloe, English spy (d. 1680)
• 1718 – David Brainerd, American missionary (d. 1747)
• 1723 – Cornelius Harnett, American merchant, farmer, and politician (d. 1781)
• 1727 – Florimond Claude, Comte de Mercy-Argenteau, Belgian-Austrian minister and diplomat (d. 1794)
• 1745 – Philippe Pinel, French physician and psychiatrist (d. 1826)
• 1748 – Georg Michael Telemann, German composer and theologian (d. 1831)
• 1808 – Napoleon III, French politician, 1st President of France, Emperor of French Second Empire (d. 1873)
• 1816 – Bogoslav Šulek, Croatian philologist, historian, and lexicographer (d. 1895)
• 1818 – Heinrich Göbel, German-American mechanic and engineer (d. 1893)
• 1826 – Dinah Craik, English author and poet (d. 1887)
• 1836 – Eli Whitney Blake, Jr., American scientist and academic (d. 1895)
• 1839 – Carol I of Romania, King of Romania (d. 1914)
• 1840 – Odilon Redon, French painter and illustrator (d. 1916)
• 1850 – Daniel Chester French, American sculptor, designed the Lincoln statue (d. 1931)
• 1851 – Alexander Dianin, Russian chemist (d. 1918)
• 1851 – Siegmund Lubin, Polish-American businessman, founded the Lubin Manufacturing Company (d. 1923)
• 1860 – Justinien de Clary, French target shooter (d. 1933)
• 1871 – Sydney Chapman, English economist and civil servant (d. 1951)
• 1873 – James Harcourt, English character actor (d. 1951)
• 1875 – Vladimir Vidrić, Croatian poet and lawyer (d. 1909)
• 1879 – Paul Poiret, French fashion designer (d. 1944)
• 1882 – Holland Smith, American general (d. 1967)
• 1884 – Princess Beatrice of Saxe-Coburg and Gotha (d. 1966)
• 1884 – Oliver Kirk, American boxer (d. 1960)
• 1884 – Daniel Varoujan, Armenian poet and educator (d. 1915)
• 1889 – Albert Jean Amateau, Turkish rabbi, lawyer, and activist (d. 1996)
• 1889 – Prince Erik, Duke of Västmanland (d. 1918)
• 1889 – Marie-Antoinette de Geuser, French mystic (d. 1918)
• 1889 – Adolf Hitler, Austrian-born German politician, Führer of Nazi Germany (d. 1945)
• 1889 – Tonny Kessler, Dutch footballer (d. 1960)
• 1890 – Maurice Duplessis, Canadian lawyer and politician, 16th Premier of Quebec (d. 1959)
• 1890 – Adolf Schärf, Austrian soldier and politician, 6th President of Austria (d. 1965)
• 1891 – Dave Bancroft, American baseball player and manager (d. 1972)
• 1893 – Harold Lloyd, American actor, comedian, and producer (d. 1971)
• 1893 – Joan Miró, Spanish painter and sculptor (d. 1983)
• 1895 – Emile Christian, American trombonist and composer (d. 1973)
• 1895 – Henry de Montherlant, French essayist, novelist, and dramatist (d. 1972)
• 1896 – Wop May, Canadian captain and pilot (d. 1952)
• 1899 – Alan Arnett McLeod, Canadian lieutenant, Victoria Cross recipient (d. 1918)

1901–present

• 1904 – Bruce Cabot, American actor (d. 1972)
• 1907 – Miran Bakhsh, Pakistani cricketer (d. 1991)
• 1907 – Augoustinos Kantiotes, Greek bishop (d. 2010)
• 1908 – Lionel Hampton, American vibraphone player, pianist, bandleader, and actor (d. 2002)
• 1910 – Fatin Rüştü Zorlu, Turkish diplomat and politician (d. 1961)
• 1913 – Mimis Fotopoulos, Greek actor and poet (d. 1986)
• 1913 – Willi Hennig, German biologist and entomologist (d. 1976)
• 1914 – Betty Lou Gerson, American actress (d. 1999)
• 1915 – Joseph Wolpe, South African psychotherapist and physician (d. 1997)
• 1916 – Nasiba Zeynalova, Azerbaijani actress (d. 2004)
• 1918 – Kai Siegbahn, Swedish physicist and academic, Nobel Prize laureate (d. 2007)
• 1919 – Richard Hillary, Australian lieutenant and pilot (d. 1943)
• 1920 – Frances Ames, South African neurologist, psychiatrist, and human rights activist (d. 2002)
• 1920 – Clement Isong, Nigerian banker and politician, Governor of Cross River State (d. 2000)
• 1920 – John Paul Stevens, American lawyer and jurist, Associate Justice of the Supreme Court of the United States (d. 2019)
• 1921 – Katarína Kolníková, Slovak actress (d. 2006)
• 1923 – Mother Angelica, American nun and broadcaster, founded Eternal Word Television Network (d. 2016)
• 1923 – Irene Lieblich, Polish-American painter and illustrator (d. 2008)
• 1923 – Tito Puente, American drummer and producer (d. 2000)
• 1924 – Nina Foch, Dutch-American actress (d. 2008)
• 1924 – Leslie Phillips, English actor and producer (d. 2022)
• 1924 – Guy Rocher, Canadian sociologist and academic
• 1925 – Ernie Stautner, German-American football player and coach (d. 2006)
• 1925 – Elena Verdugo, American actress (d. 2017)
• 1927 – Bud Cullen, Canadian judge and politician, 1st Canadian Minister of Employment and Immigration (d. 2005)
• 1927 – Phil Hill, American race car driver (d. 2008)
• 1927 – K. Alex Müller, Swiss physicist and academic, Nobel Prize laureate (d. 2023)
• 1928 – Robert Byrne, American chess player and author (d. 2013)
• 1928 – Johnny Gavin, Irish international footballer (d. 2007)
• 1929 – Harry Agganis, American baseball and football player (d. 1955)
• 1929 – Bobby Hollander, American film director, actor, and magazine publisher (d. 2002)
• 1930 – Dwight Gustafson, American composer and conductor (d. 2014)
• 1930 – Antony Jay, English director and screenwriter (d. 2016)
• 1931 – Michael Allenby, 3rd Viscount Allenby, English lieutenant and politician (d. 2014)
• 1931 – John Eccles, 2nd Viscount Eccles, English businessman and politician
• 1932 – Myriam Bru, French actress
• 1936 – Lisa Davis, English-American actress
• 1936 – Pauli Ellefsen, Faroese technician, surveyor, and politician, 6th Prime Minister of the Faroe Islands (d. 2012)
• 1936 – Pat Roberts, American captain, journalist, and politician
• 1937 – Jiří Dienstbier, Czech journalist and politician, Czech Minister of Foreign Affairs (d. 2011)
• 1937 – Harvey Quaytman, American painter and educator (d. 2002)
• 1937 – George Takei, American actor
• 1938 – Betty Cuthbert, Australian sprinter (d. 2017)
• 1938 – Manfred Kinder, German runner
• 1938 – Eszter Tamási, Hungarian actress (d. 1991)
• 1939 – Peter S. Beagle, American author and screenwriter
• 1939 – Gro Harlem Brundtland, Norwegian physician and politician, 22nd Prime Minister of Norway
• 1939 – Johnny Tillotson, American singer-songwriter
• 1940 – James Gammon, American actor (d. 2010)
• 1941 – Ryan O'Neal, American actor (d. 2023)
• 1943 – Alan Beith, English academic and politician
• 1943 – John Eliot Gardiner, English conductor and director
• 1944 – Toivo Aare, Estonian journalist and author (d. 1999)
• 1945 – Michael Brandon, American actor and director
• 1945 – Olga Karlatos, Greek actress and Bermudian lawyer
• 1945 – Thein Sein, Burmese general and politician, 8th President of Burma
• 1945 – Naftali Temu, Kenyan runner (d. 2003)
• 1945 – Steve Spurrier, American football player and coach
• 1945 – Mike, American Wyandotte chicken, lived 18 months following decapitation (d. 1947)
• 1946 – Sandro Chia, Italian painter and sculptor
• 1947 – Rita Dionne-Marsolais, Canadian economist and politician
• 1947 – Viktor Suvorov, Russian intelligence officer, historian, and author
• 1948 – Matthias Kuhle, German geographer and academic (d. 2015)
• 1949 – Veronica Cartwright, English-American actress
• 1949 – Toller Cranston, Canadian-Mexican figure skater and painter (d. 2015)
• 1949 – Massimo D'Alema, Italian journalist and politician, 76th Prime Minister of Italy
• 1949 – Jessica Lange, American actress
• 1950 – Alexander Lebed, Russian general and politician (d. 2002)
• 1950 – N. Chandrababu Naidu, Indian politician, 13th Chief Minister of Andhra Pradesh
• 1951 – Luther Vandross, American singer-songwriter and producer (d. 2005)
• 1952 – Louka Katseli, Greek economist and politician
• 1953 – Sebastian Faulks, English journalist and author
• 1955 – Donald Pettit, American engineer and astronaut
• 1955 – Svante Pääbo, Swedish geneticist and Nobel Laureate
• 1956 – Beatrice Ask, Swedish politician, Swedish Minister for Justice
• 1956 – Peter Chelsom, English film director, writer, and actor
• 1956 – Kakha Bendukidze, Georgian economist and politician (d. 2014)
• 1958 – Viacheslav Fetisov, Russian ice hockey player and coach
• 1960 – Debbie Flintoff-King, Australian hurdler and coach
• 1961 – Don Mattingly, American baseball player, coach, and manager
• 1961 – Konstantin Lavronenko, Russian actor
• 1963 – Rachel Whiteread, English sculptor
• 1964 – John Carney, American football player
• 1964 – Crispin Glover, American actor and filmmaker
• 1964 – Andy Serkis, English actor and director
• 1964 – Rosalynn Sumners, American figure skater
• 1965 – Kostis Chatzidakis, Greek politician, Ministry of Economy, Infrastructure, Shipping and Tourism
• 1965 – Léa Fazer, Swiss film director, screenwriter and actress
• 1966 – David Chalmers, Australian philosopher and academic
• 1966 – David Filo, American businessman, co-founded Yahoo!
• 1967 – Mike Portnoy, American drummer and songwriter
• 1968 – Julia Morris, Australian entertainer
• 1969 – Felix Baumgartner, Austrian daredevil
• 1969 – Will Hodgman, Australian politician, 45th Premier of Tasmania
• 1970 – Shemar Moore, American actor
• 1971 – Allan Houston, American basketball player
• 1972 – Carmen Electra, American model and actress
• 1972 – Stephen Marley, Jamaican-American musician
• 1973 – Julie Powell, American food writer and memoirist (d. 2022)
• 1975 – Killer Mike, American rapper
• 1978 – Carl Greenidge, English cricketer
• 1980 – Emma Husar, Australian politician
• 1983 – Miranda Kerr, Australian model
• 1987 – Jorge Pinto, Portuguese politician
• 1988 – Brandon Belt, American baseball player
• 1989 – Vannesa Rosales, Venezuelan activist and teacher
• 1990 – Jason Behrendorff, Australian cricketer
• 1991 – Luke Kuechly, American football player
• 1997 – Alexander Zverev, German tennis player

Pre-1600

• 689 – Cædwalla, king of Wessex (b. 659)
• 888 – Xi Zong, Chinese emperor (b. 862)
• 1099 – Peter Bartholomew (b. 1061)
• 1164 – Antipope Victor IV
• 1176 – Richard de Clare, 2nd Earl of Pembroke, English-Irish politician, Lord Chief Justice of Ireland (b. 1130)
• 1248 – Güyük Khan, Mongol ruler, 3rd Great Khan of the Mongol Empire (b. 1206)
• 1284 – Hōjō Tokimune, regent of Japan (b. 1251)
• 1314 – Pope Clement V (b. 1264)
• 1322 – Simon Rinalducci, Italian Augustinian friar
• 1502 – Mary of Looz-Heinsberg, Dutch noble (b. 1424)
• 1521 – Zhengde, Chinese emperor (b. 1491)
• 1534 – Elizabeth Barton, English nun and martyr (b. 1506)
• 1558 – Johannes Bugenhagen, German priest and theologian (b. 1485)

1601–1900

• 1643 – Christoph Demantius, German composer and poet (b. 1567)
• 1703 – Lancelot Addison, English clergyman and educator (b. 1632)
• 1769 – Chief Pontiac, American tribal leader (b. 1720)
• 1831 – John Abernethy, English surgeon and anatomist (b. 1764)
• 1873 – William Tite, English architect, designed the Royal Exchange (b. 1798)
• 1874 – Alexander H. Bailey, American lawyer, judge, and politician (b. 1817)
• 1881 – William Burges, English architect and designer (b. 1827)
• 1886 – Charles-François-Frédéric, marquis de Montholon-Sémonville, French general and diplomat, French ambassador to the United States (b. 1814)
• 1887 – Muhammad Sharif Pasha, Greek-Egyptian politician, 2nd Prime Minister of Egypt (b. 1826)
• 1899 – Joseph Wolf, German ornithologist and illustrator (b. 1820)

1901–present

• 1902 – Joaquim de Sousa Andrade, Brazilian poet and educator (b. 1833)
• 1912 – Bram Stoker, Anglo-Irish novelist and critic, created Count Dracula (b. 1847)
• 1918 – Jussi Merinen, Finnish politician (b. 1873)
• 1918 – Karl Ferdinand Braun, German-American physicist and academic, Nobel Prize laureate (b. 1850)
• 1927 – Enrique Simonet, Spanish painter and educator (b. 1866)
• 1929 – Prince Henry of Prussia (b. 1862)
• 1931 – Sir Cosmo Duff-Gordon, 5th Baronet, Scottish-English fencer and businessman (b. 1862)
• 1932 – Giuseppe Peano, Italian mathematician and philosopher (b. 1858)
• 1935 – John Cameron, Scottish footballer and manager (b. 1872)
• 1935 – Lucy, Lady Duff-Gordon, English fashion designer (b. 1863)
• 1942 – Jüri Jaakson, Estonian businessman and politician, 6th State Elder of Estonia (b. 1870)
• 1944 – Elmer Gedeon, American baseball player and pilot (b. 1917)
• 1945 – Erwin Bumke, Polish-German jurist and politician (b. 1874)
• 1946 – Mae Busch, Australian actress (b. 1891)
• 1947 – Christian X of Denmark (b. 1870)
• 1951 – Ivanoe Bonomi, Italian politician, 25th Prime Minister of Italy (b. 1873)
• 1961 – Ado Vabbe, Estonian painter (b. 1892)
• 1967 – Léo-Paul Desrosiers, Canadian journalist and author (b. 1896)
• 1968 – Rudolph Dirks, German-American illustrator (b. 1877)
• 1969 – Vjekoslav Luburić, Croatian Ustaše official and concentration camp administrator (b. 1914)
• 1980 – M. Canagaratnam, Sri Lankan politician (b. 1924)
• 1982 – Archibald MacLeish, American poet, playwright, and lawyer (b. 1892)
• 1986 – Sibte Hassan, Pakistani journalist, scholar, and activist (b. 1916)
• 1991 – Steve Marriott, English singer-songwriter and producer (b. 1947)
• 1991 – Don Siegel, American director and producer (b. 1912)
• 1992 – Marjorie Gestring, American springboard diver (b. 1922)
• 1992 – Benny Hill, English comedian, actor, and screenwriter (b. 1924)
• 1993 – Cantinflas, Mexican actor, producer, and screenwriter (b. 1911)
• 1995 – Milovan Đilas, Yugoslav communist, politician, theorist and author (b. 1911)
• 1996 – Trần Văn Trà, Vietnamese general and politician (b. 1918)
• 1999 – Rick Rude, American professional wrestler (b. 1958)
• 1999 – Rachel Scott, American victim of Columbine High School massacre (b.1981)
• 1999 – Cassie Bernall, American victim of Columbine High School massacre (b. 1981)
• 2001 – Giuseppe Sinopoli, Italian conductor and composer (b. 1946)
• 2002 – Alan Dale, American singer (b. 1925)
• 2003 – Bernard Katz, German-English biophysicist and academic, Nobel Prize laureate (b. 1911)
• 2004 – Lizzy Mercier Descloux, French musician, singer-songwriter, composer, actress, writer and painter (b. 1956)
• 2005 – Fumio Niwa, Japanese journalist and author (b. 1904)
• 2007 – Andrew Hill, American pianist, composer, and bandleader (b. 1931)
• 2007 – Michael Fu Tieshan, Chinese bishop (b. 1931)
• 2008 – Monica Lovinescu, Romanian journalist and author (b. 1923)
• 2010 – Dorothy Height, American educator and activist (b. 1912)
• 2011 – Tim Hetherington, English photographer and journalist (b. 1970)
• 2012 – Bert Weedon, English guitarist and songwriter (b. 1920)
• 2014 – Neville Wran, Australian politician, 35th Premier of New South Wales (b. 1926)
• 2016 – Victoria Wood, British comedian, actress and writer (b. 1953)
• 2018 – Avicii, Swedish DJ and musician (b. 1989)
• 2021 – Idriss Déby, Chadian politician and military officer (b. 1952)
• 2021 – Monte Hellman, American film director (b. 1929)
• 2021 – Les McKeown, Scottish pop singer (b. 1955)
• 2022 – Gavin Millar, Scottish film director (b. 1938)
• 2024 – Antonio Cantafora, Italian film and television actor (b. 1944)
• 2024 – Roman Gabriel, Filipino-American NBA American footballer
• 2024 – Lourdes Portillo, Mexican film director, producer, and writer (b. 1943)

• Christian feast day:
  • Agnes of Montepulciano
  • Beuno
  • Johannes Bugenhagen (Lutheran)
  • Theotimos
  • April 20 (Eastern Orthodox liturgics)
• 420 (cannabis culture)
• UN Chinese Language Day (United Nations)