| 142591 | December 18 | Birth | 1993 – Riria, Japanese actress |
| 142592 | December 18 | Death | 821 – Theodulf of Orléans, Spanish bishop and poet (b. 750) |
| 142593 | December 18 | Death | 1075 – Edith of Wessex (b. 1025) |
| 142594 | December 18 | Death | 1133 – Hildebert, French poet and scholar (b. 1055) |
| 142595 | December 18 | Death | 1495 – Alfonso II of Naples (b. 1448) |
| 142596 | December 18 | Death | 1591 – Marigje Arriens, Dutch woman accused of witchcraft (b. 1520) |
| 142597 | December 18 | Death | 1651 – William Brabazon, 1st Earl of Meath (b. 1580) |
| 142598 | December 18 | Death | 1692 – Veit Ludwig von Seckendorff, German scholar and politician (b. 1626) |
| 142599 | December 18 | Death | 1737 – Antonio Stradivari, Italian instrument maker (b. 1644) |
| 142600 | December 18 | Death | 1787 – Soame Jenyns, English poet and politician (b. 1704) |
| 142601 | December 18 | Death | 1799 – Jean-Étienne Montucla, French mathematician and historian (b. 1725) |
| 142602 | December 18 | Death | 1803 – Johann Gottfried Herder, German philosopher, theologian, and poet (b. 1744) |
| 142603 | December 18 | Death | 1829 – Jean-Baptiste Lamarck, French soldier, biologist, and academic (b. 1744) |
| 142604 | December 18 | Death | 1843 – Thomas Graham, 1st Baron Lynedoch, Scottish-English general and politician (b. 1748) |
| 142605 | December 18 | Death | 1848 – Bernard Bolzano, Bohemian priest and mathematician (b. 1781) |
| 142606 | December 18 | Death | 1869 – Louis Moreau Gottschalk, American pianist and composer (b. 1829) |
| 142607 | December 18 | Death | 1880 – Michel Chasles, French mathematician and academic (b. 1793) |
| 142608 | December 18 | Death | 1892 – Richard Owen, English biologist, anatomist, and paleontologist (b. 1804) |
| 142609 | December 18 | Death | 1922 – Sir Carl Meyer, 1st Baronet, German-English banker and businessman (b. 1851) |
| 142610 | December 18 | Death | 1936 – Andrija Mohorovičić, Croatian meteorologist and seismologist (b. 1857) |
| 142611 | December 18 | Death | 1939 – Ernest Lawson, Canadian-American painter (b. 1873) |
| 142612 | December 18 | Death | 1944 – Alexander Cudmore, American soccer player (b. 1888) |
| 142613 | December 18 | Death | 1950 – Johnny Hyde, Russian-American talent agent (b. 1895) |
| 142614 | December 18 | Death | 1968 – Joan Tabor, American actress (b. 1932) |
| 142615 | December 18 | Death | 1969 – Charles Dvorak, American pole vaulter and coach (b. 1878) |
| 142616 | December 18 | Death | 1971 – Bobby Jones, American golfer and lawyer (b. 1902) |
| 142617 | December 18 | Death | 1971 – Diana Lynn, American actress and singer (b. 1926) |
| 142618 | December 18 | Death | 1973 – Allamah Rasheed Turabi, Indian-Pakistani religious leader and philosopher (b. 1908) |
| 142619 | December 18 | Death | 1974 – Harry Hooper, American baseball player, coach, and manager (b. 1887) |
| 142620 | December 18 | Death | 1975 – Theodosius Dobzhansky, Ukrainian geneticist and biologist (b. 1900) |