| 120151 | October 20 | Birth | 1985 – Alphonso Smith, American football player |
| 120152 | October 20 | Birth | 1985 – James Sutton, English race car driver |
| 120153 | October 20 | Birth | 1986 – Wanlop Saechio, Thai footballer |
| 120154 | October 20 | Birth | 1987 – Raphael Hackl, German rugby player |
| 120155 | October 20 | Birth | 1987 – Sanne Nijhof, Dutch model |
| 120156 | October 20 | Birth | 1988 – Ma Long, Chinese table tennis player |
| 120157 | October 20 | Birth | 1988 – Risa Niigaki, Japanese singer and actress (Morning Musume, Tanpopo, Sakuragumi, and Athena & Robikerottsu) |
| 120158 | October 20 | Birth | 1988 – Candice Swanepoel, South African model |
| 120159 | October 20 | Birth | 1989 – Jess Glynne, English singer-songwriter |
| 120160 | October 20 | Birth | 1989 – Colin Wilson, Canadian-American ice hockey player |
| 120161 | October 20 | Birth | 1992 – Mattia De Sciglio, Italian footballer |
| 120162 | October 20 | Birth | 1992 – John Egan, Irish footballer |
| 120163 | October 20 | Birth | 1992 – Kristian Ipsen, American diver |
| 120164 | October 20 | Birth | 1992 – Liis Lemsalu, Estonian singer |
| 120165 | October 20 | Birth | 1992 – Ksenia Semyonova, Russian gymnast |
| 120166 | October 20 | Birth | 1992 – Ferhat Yazgan, Turkish footballer |
| 120167 | October 20 | Birth | 1993 – Hunter King, American actress |
| 120168 | October 20 | Birth | 1994 – Morgan Featherstone, Australian model |
| 120169 | October 20 | Birth | 1994 – Corey Oates, Australian rugby player |
| 120170 | October 20 | Birth | 1995 – Zhenwei Wang, Chinese actor and martial artist |
| 120171 | October 20 | Death | 460 – Aelia Eudocia, Byzantine wife of Theodosius II (b. 401) |
| 120172 | October 20 | Death | 1139 – Henry X, Duke of Bavaria (b. 1108) |
| 120173 | October 20 | Death | 1524 – Thomas Linacre, English physician and scholar (b. 1460) |
| 120174 | October 20 | Death | 1570 – João de Barros, Portuguese historian and author (b. 1496) |
| 120175 | October 20 | Death | 1631 – Michael Maestlin, German astronomer and mathematician (b. 1550) |
| 120176 | October 20 | Death | 1640 – John Ball, English clergyman and theologian (b. 1585) |
| 120177 | October 20 | Death | 1652 – Antonio Coello, Spanish poet and playwright (b. 1611) |
| 120178 | October 20 | Death | 1713 – Archibald Pitcairne, Scottish physician and academic (b. 1652) |
| 120179 | October 20 | Death | 1740 – Charles VI, Holy Roman Emperor (b. 1685) |
| 120180 | October 20 | Death | 1842 – Grace Darling, English heroine (b. 1815) |