| 38881 | April 4 | Death | 1609 – Carolus Clusius, Flemish botanist, mycologist, and academic (b. 1526) |
| 38882 | April 4 | Death | 1617 – John Napier, Scottish mathematician, physicist, and astronomer (b. 1550) |
| 38883 | April 4 | Death | 1643 – Simon Episcopius, Dutch theologian and academic (b. 1583) |
| 38884 | April 4 | Death | 1661 – Alexander Leslie, 1st Earl of Leven, Scottish-Swedish field marshal (b. 1580) |
| 38885 | April 4 | Death | 1701 – Joseph Haines, English actor, singer, and dancer |
| 38886 | April 4 | Death | 1743 – Daniel Neal, English historian and author (b. 1678) |
| 38887 | April 4 | Death | 1761 – Théodore Gardelle, Swiss painter (b. 1722) |
| 38888 | April 4 | Death | 1766 – John Taylor, English librarian and scholar (b. 1704) |
| 38889 | April 4 | Death | 1774 – Oliver Goldsmith, Irish author, poet, and playwright (b. 1728) |
| 38890 | April 4 | Death | 1792 – James Sykes, American lawyer and politician (b. 1725) |
| 38891 | April 4 | Death | 1807 – Jérôme Lalande, French astronomer and academic (b. 1732) |
| 38892 | April 4 | Death | 1817 – André Masséna, French general (b. 1758) |
| 38893 | April 4 | Death | 1841 – William Henry Harrison, American general and politician, 9th President of the United States (b. 1773) |
| 38894 | April 4 | Death | 1846 – Solomon Sibley, American lawyer and politician, 1st Mayor of Detroit (b. 1769) |
| 38895 | April 4 | Death | 1861 – John McLean, American jurist and politician, 6th United States Postmaster General (b. 1785) |
| 38896 | April 4 | Death | 1863 – Ludwig Emil Grimm, German painter and engraver (b. 1790) |
| 38897 | April 4 | Death | 1864 – Joseph Pitty Couthouy, American commander and paleontologist (b. 1808) |
| 38898 | April 4 | Death | 1870 – Heinrich Gustav Magnus, German chemist and physicist (b. 1802) |
| 38899 | April 4 | Death | 1874 – Charles Ernest Beulé, French archaeologist and politician (b. 1826) |
| 38900 | April 4 | Death | 1875 – Karl Mauch, German geographer and explorer (b. 1837) |
| 38901 | April 4 | Death | 1878 – Richard M. Brewer, American criminal (b. 1850) |
| 38902 | April 4 | Death | 1879 – Heinrich Wilhelm Dove, German physicist and meteorologist (b. 1803) |
| 38903 | April 4 | Death | 1883 – Peter Cooper, American businessman and philanthropist, founded Cooper Union (b. 1791) |
| 38904 | April 4 | Death | 1890 – Pierre-Joseph-Olivier Chauveau, Canadian lawyer and politician, 1st Premier of Quebec (b. 1820) |
| 38905 | April 4 | Death | 1890 – Edmond Hébert, French geologist and academic (b. 1812) |
| 38906 | April 4 | Death | 1912 – Charles Brantley Aycock, American lawyer and politician, 50th Governor of North Carolina (b. 1859) |
| 38907 | April 4 | Death | 1912 – Isaac K. Funk, American minister, lexicographer, and publisher, co-founded Funk & Wagnalls (b. 1839) |
| 38908 | April 4 | Death | 1919 – William Crookes, English chemist and physicist (b. 1832) |
| 38909 | April 4 | Death | 1919 – Francisco Marto, Portuguese saint (b. 1908) |
| 38910 | April 4 | Death | 1923 – John Venn, English mathematician and philosopher, created the Venn diagram (b. 1834) |