| 120571 | October 21 | Death | 1600 – Shima Sakon, Japanese samurai (b. 1540) |
| 120572 | October 21 | Death | 1600 – Toda Katsushige, Japanese daimyo (b. 1557) |
| 120573 | October 21 | Death | 1623 – William Wade, English politician and diplomat, Lieutenant of the Tower of London (b. 1546) |
| 120574 | October 21 | Death | 1662 – Henry Lawes, English pianist and composer (b. 1595) |
| 120575 | October 21 | Death | 1687 – Edmund Waller, English poet and politician (b. 1606) |
| 120576 | October 21 | Death | 1765 – Giovanni Paolo Panini, Italian painter and architect (b. 1691) |
| 120577 | October 21 | Death | 1775 – Peyton Randolph, American lawyer and politician, 1st President of the Continental Congress (b. 1721) |
| 120578 | October 21 | Death | 1777 – Samuel Foote, English actor and playwright (b. 1720) |
| 120579 | October 21 | Death | 1805 – John Cooke, English captain (b. 1763) |
| 120580 | October 21 | Death | 1805 – George Duff, Scottish captain (b. 1764) |
| 120581 | October 21 | Death | 1805 – Horatio Nelson, 1st Viscount Nelson, English admiral (b. 1758) |
| 120582 | October 21 | Death | 1821 – Dorothea Ackermann, German actress (b. 1752) |
| 120583 | October 21 | Death | 1835 – Muthuswami Dikshitar, Indian poet and composer (b. 1775) |
| 120584 | October 21 | Death | 1872 – Jacques Babinet, French physicist, mathematician, and astronomer (b. 1794) |
| 120585 | October 21 | Death | 1873 – Johan Sebastian Welhaven, Norwegian author, poet, and critic (b. 1807) |
| 120586 | October 21 | Death | 1896 – James Henry Greathead, South African-English engineer (b. 1844) |
| 120587 | October 21 | Death | 1903 – Jinmaku Kyūgorō, Japanese sumo wrestler, the 12th Yokozuna (b. 1829) |
| 120588 | October 21 | Death | 1904 – Isabelle Eberhardt, Swiss explorer and journalist (b. 1877) |
| 120589 | October 21 | Death | 1907 – Jules Chevalier, French priest, founded the Missionaries of the Sacred Heart (b. 1824) |
| 120590 | October 21 | Death | 1931 – Arthur Schnitzler, Austrian author and playwright (b. 1862) |
| 120591 | October 21 | Death | 1938 – Dorothy Hale, American actress (b. 1905) |
| 120592 | October 21 | Death | 1940 – William G. Conley, American journalist, lawyer, and politician, 18th Governor of West Virginia (b. 1866) |
| 120593 | October 21 | Death | 1944 – Alois Kayser, German-French missionary (b. 1877) |
| 120594 | October 21 | Death | 1952 – Hans Merensky, South African geologist and philanthropist (b. 1871) |
| 120595 | October 21 | Death | 1963 – Józef Franczak, Polish sergeant (b. 1918) |
| 120596 | October 21 | Death | 1965 – Bill Black, American bass player and bandleader (The Blue Moon Boys) (b. 1926) |
| 120597 | October 21 | Death | 1969 – Jack Kerouac, American author and poet (b. 1922) |
| 120598 | October 21 | Death | 1969 – Wacław Sierpiński, Polish mathematician and academic (b. 1882) |
| 120599 | October 21 | Death | 1973 – Nasif Estéfano, Argentinian race car driver (b. 1932) |
| 120600 | October 21 | Death | 1975 – Charles Reidpath, American runner and general (b. 1887) |