| 124261 | October 31 | Event | 2003 – Mahathir bin Mohamad resigns as Prime Minister of Malaysia and is replaced by Deputy Prime Minister Abdullah Ahmad Badawi, marking an end to Mahathir's 22 years in power. |
| 124262 | October 31 | Event | 2003 – United Nations Convention against Corruption is adopted. |
| 124263 | October 31 | Event | 2011 – The global population of humans reaches seven billion. This day is now recognized by the United Nations as Seven Billion Day. |
| 124264 | October 31 | Event | 2014 – Virgin Galactic's SpaceShipTwo crashes in the Mojave Desert during a test flight. |
| 124265 | October 31 | Event | 2015 – Kogalymavia Flight 9268 crashes in Egypt's Sinai Peninsula, killing all 224 people on board. |
| 124266 | October 31 | Birth | 1291 – Philippe de Vitry, French composer, poet, and theorist (d. 1361) |
| 124267 | October 31 | Birth | 1345 – Ferdinand I of Portugal (d. 1383) |
| 124268 | October 31 | Birth | 1391 – Edward, King of Portugal (d. 1438) |
| 124269 | October 31 | Birth | 1424 – Władysław III of Poland (d. 1444) |
| 124270 | October 31 | Birth | 1599 – Denzil Holles, 1st Baron Holles, English politician (d. 1680) |
| 124271 | October 31 | Birth | 1620 – John Evelyn, English gardener and author (d. 1706) |
| 124272 | October 31 | Birth | 1636 – Ferdinand Maria, Elector of Bavaria (d. 1679) |
| 124273 | October 31 | Birth | 1686 – Senesino, Italian singer and actor (d. 1758) |
| 124274 | October 31 | Birth | 1692 – Anne Claude de Caylus, French archaeologist and author (d. 1765) |
| 124275 | October 31 | Birth | 1694 – Yeongjo of Joseon (d. 1776) |
| 124276 | October 31 | Birth | 1705 – Pope Clement XIV (d. 1774) |
| 124277 | October 31 | Birth | 1711 – Laura Bassi, Italian physician, physicist, and academic (d. 1778) |
| 124278 | October 31 | Birth | 1724 – Christopher Anstey, English author and poet (d. 1805) |
| 124279 | October 31 | Birth | 1737 – James Lovell, American educator and politician (d. 1789) |
| 124280 | October 31 | Birth | 1795 – John Keats, English poet (d. 1821) |
| 124281 | October 31 | Birth | 1815 – Karl Weierstrass, German mathematician and academic (d. 1897) |
| 124282 | October 31 | Birth | 1825 – Charles Lavigerie, French-Algerian cardinal and academic (d. 1892) |
| 124283 | October 31 | Birth | 1827 – Richard Morris Hunt, American architect, designed the New York Tribune Building (d. 1895) |
| 124284 | October 31 | Birth | 1831 – Paolo Mantegazza, Italian neurologist, physiologist, and anthropologist (d. 1910) |
| 124285 | October 31 | Birth | 1835 – Adelbert Ames, American general and politician, 27th Governor of Mississippi (d. 1933) |
| 124286 | October 31 | Birth | 1835 – Krišjānis Barons, Latvian linguist and author (d. 1923) |
| 124287 | October 31 | Birth | 1835 – Adolf von Baeyer, German chemist and academic, Nobel Prize laureate (d. 1917) |
| 124288 | October 31 | Birth | 1838 – Luís I of Portugal (d. 1889) |
| 124289 | October 31 | Birth | 1840 – Franz Müller, German tailor and murderer (d. 1864) |
| 124290 | October 31 | Birth | 1847 – Galileo Ferraris, Italian physicist and engineer (d. 1897) |