| 42031 | April 12 | Birth | 1851 – Edward Walter Maunder, English astronomer and author (d. 1928) |
| 42032 | April 12 | Birth | 1852 – Ferdinand von Lindemann, German mathematician and academic (d. 1939) |
| 42033 | April 12 | Birth | 1856 – Martin Conway, 1st Baron Conway of Allington, English mountaineer, cartographer, and politician (d. 1937) |
| 42034 | April 12 | Birth | 1861 – Walter Bingle, Australian public servant (d. 1928) |
| 42035 | April 12 | Birth | 1866 – Princess Viktoria of Prussia (d. 1929) |
| 42036 | April 12 | Birth | 1868 – Akiyama Saneyuki, Japanese admiral (d. 1918) |
| 42037 | April 12 | Birth | 1868 – Ella Gaunt Smith, American businesswoman (d. 1932) |
| 42038 | April 12 | Birth | 1869 – Henri Désiré Landru, French serial killer (d. 1922) |
| 42039 | April 12 | Birth | 1871 – Ioannis Metaxas, Greek general and politician, 130th Prime Minister of Greece (d. 1941) |
| 42040 | April 12 | Birth | 1874 – William B. Bankhead, American lawyer and politician, 47th Speaker of the United States House of Representatives (d. 1940) |
| 42041 | April 12 | Birth | 1880 – Addie Joss, American baseball player and journalist (d. 1911) |
| 42042 | April 12 | Birth | 1883 – Imogen Cunningham, American photographer and educator (d. 1976) |
| 42043 | April 12 | Birth | 1883 – Dally Messenger, Australian rugby player, cricketer, and sailor (d. 1959) |
| 42044 | April 12 | Birth | 1884 – Tenby Davies, Welsh runner (d. 1932) |
| 42045 | April 12 | Birth | 1884 – Otto Meyerhof, German physician and biochemist, Nobel Prize laureate (d. 1951) |
| 42046 | April 12 | Birth | 1885 – Robert Delaunay, French painter (d. 1941) |
| 42047 | April 12 | Birth | 1887 – Harold Lockwood, American actor and director (d. 1918) |
| 42048 | April 12 | Birth | 1888 – Dan Ahearn, Irish-American long jumper and police officer (d. 1942) |
| 42049 | April 12 | Birth | 1888 – Cecil Kimber, English automobile engineer (d. 1945) |
| 42050 | April 12 | Birth | 1888 – Kaarlo Koskelo, Finnish-American wrestler (d. 1953) |
| 42051 | April 12 | Birth | 1888 – Heinrich Neuhaus, Ukrainian-Russian pianist and educator (d. 1964) |
| 42052 | April 12 | Birth | 1892 – Johnny Dodds, American clarinet player and saxophonist (d. 1940) |
| 42053 | April 12 | Birth | 1893 – Robert Harron, American actor (d. 1920) |
| 42054 | April 12 | Birth | 1894 – Francisco Craveiro Lopes, Portuguese field marshal and politician, 13th President of Portugal (d. 1964) |
| 42055 | April 12 | Birth | 1898 – Lily Pons, French-American soprano and actress (d. 1976) |
| 42056 | April 12 | Birth | 1901 – Lowell Stockman, American farmer and politician (d. 1962) |
| 42057 | April 12 | Birth | 1902 – Louis Beel, Dutch academic and politician, 36th Prime Minister of the Netherlands (d. 1977) |
| 42058 | April 12 | Birth | 1903 – Jan Tinbergen, Dutch economist and academic, Nobel Prize laureate (d. 1994) |
| 42059 | April 12 | Birth | 1907 – Zawgyi, Burmese poet, author, literary historian, critic, scholar and academic (d. 1990) |
| 42060 | April 12 | Birth | 1907 – Felix de Weldon, Austrian-American sculptor, designed the Marine Corps War Memorial (d. 2003) |