| April 1 | Sergei Rachmaninoff, b. 1873 |
| April 2 | Hans Christian Andersen, b. 1805 |
| April 3 | Washington Irving, b. 1783 |
| April 4 | Sir William Siemens, b. 1823 |
| April 5 | Thomas Hobbes, b. 1588 |
| April 6 | Raffaeloo Sanzio (Raphael), b. 1483 |
| April 7 | William Wordsworth, b. 1770 |
| April 8 | The Great Western inaugurates regular transatlantic steamship service, 1838 |
| April 9 | Isambard Kingdom Brunel, b. 1806 |
| April l0 | Hugo Grotius, b. 1583 |
| April 11 | William and Mary crowned in Glorious Revolution, 1689 |
| April 12 | Otto Meyerhof, b. 1884 |
| April 13 | Thomas Jefferson, b. 1743 |
| April 14 | Christian Huygens, b. 1629 |
| April 15 | Leonardo da Vinci, b. 1452 |
| April 16 | Wilbur Wright, b. 1867 |
| April 17 | J. Pierpont Morgan, b. 1837 |
| April 18 | David Ricardo, b. 1772 |
| April 19 | First battle of the American Revolution, at Lexington, 1775 |
| April 20 | Daniel Chester French, b. 1850 |
| April 21 | Catherine the Great, b. 1729 |
| April 22 | Henry Fielding, b. 1707 |
| April 23 | William Shakespeare, b. 1564 |
| April 24 | Edmund Cartwright, b. 1743 |
| April 25 | Guglielmo Marconi, b. 1874 |
| April 26 | Eugène Delacroix, b. 1798 |
| April 27 | Samuel F. B. Morse, b. 1791 |
| April 28 | James Monroe, b. 1758 |
| April 29 | Henri Poincaré, b. 1854 |
| April 30 | Karl Friedrich Gauss, b. 1777 |