| 122731 | October 27 | Event | 1954 – Benjamin O. Davis, Jr. becomes the first African-American general in the United States Air Force. |
| 122732 | October 27 | Event | 1958 – Iskander Mirza, the first President of Pakistan, is deposed in a bloodless coup d'état by General Ayub Khan, who had been appointed the enforcer of martial law by Mirza 20 days earlier. |
| 122733 | October 27 | Event | 1961 – NASA tests the first Saturn I rocket in Mission Saturn-Apollo 1. |
| 122734 | October 27 | Event | 1961 – Mauritania and Mongolia join the United Nations. |
| 122735 | October 27 | Event | 1962 – Major Rudolf Anderson of the United States Air Force becomes the only direct human casualty of the Cuban Missile Crisis when his U-2 reconnaissance airplane is shot down in Cuba by a Soviet-supplied SA-2 Guideline surface-to-air missile. |
| 122736 | October 27 | Event | 1962 – A plane carrying Enrico Mattei, post-war Italian administrator, crashes in mysterious circumstances. |
| 122737 | October 27 | Event | 1964 – Ronald Reagan delivers a speech on behalf of Republican candidate for president, Barry Goldwater. The speech launched his political career and came to be known as "A Time for Choosing". |
| 122738 | October 27 | Event | 1967 – Catholic priest Philip Berrigan and others of the 'Baltimore Four' protest the Vietnam War by pouring blood on Selective Service records. |
| 122739 | October 27 | Event | 1971 – The Democratic Republic of the Congo is renamed Zaire. |
| 122740 | October 27 | Event | 1973 – A 1.4 kg chondrite-type meteorite strikes in Cañon City, Colorado. |
| 122741 | October 27 | Event | 1979 – Saint Vincent and the Grenadines gains its independence from the United Kingdom. |
| 122742 | October 27 | Event | 1981 – The Soviet submarine U 137 runs aground on the east coast of Sweden. |
| 122743 | October 27 | Event | 1986 – The British government suddenly deregulates financial markets, leading to a total restructuring of the way in which they operate in the country, in an event now referred to as the Big Bang. |
| 122744 | October 27 | Event | 1988 – Ronald Reagan decides to tear down the new U.S. Embassy in Moscow because of Soviet listening devices in the building structure. |
| 122745 | October 27 | Event | 1991 – Turkmenistan achieves independence from the Soviet Union. |
| 122746 | October 27 | Event | 1992 – United States Navy radioman Allen R. Schindler, Jr. is brutally murdered by shipmate Terry M. Helvey for being gay, precipitating first military, then national, debate about gays in the military that resulted in the United States "Don't ask, don't |
| 122747 | October 27 | Event | 1994 – Gliese 229B is the first Substellar Mass Object to be unquestionably identified. |
| 122748 | October 27 | Event | 1995 – Former Prime Minister of Italy Bettino Craxi is convicted in absentia of corruption. |
| 122749 | October 27 | Event | 1997 – October 27, 1997 mini-crash: Stock markets around the world crash because of fears of a global economic meltdown. The Dow Jones Industrial Average plummets 554.26 points to 7,161.15. |
| 122750 | October 27 | Event | 1999 – Gunmen open fire in the Armenian Parliament, killing Prime Minister Vazgen Sargsyan, Parliament Chairman Karen Demirchyan, and six other members. |
| 122751 | October 27 | Event | 2005 – Riots begin in Paris after the deaths of two Muslim teenagers. |
| 122752 | October 27 | Birth | 921 – Chai Rong, Chinese emperor (d. 959) |
| 122753 | October 27 | Birth | 1156 – Raymond VI, Count of Toulouse (d. 1222) |
| 122754 | October 27 | Birth | 1335 – Taejo of Joseon (d. 1408) |
| 122755 | October 27 | Birth | 1401 – Catherine of Valois (d. 1437) |
| 122756 | October 27 | Birth | 1703 – Johann Gottlieb Graun, German violinist and composer (d. 1771) |
| 122757 | October 27 | Birth | 1744 – Mary Moser, English painter and academic (d. 1819) |
| 122758 | October 27 | Birth | 1760 – August Neidhardt von Gneisenau, Prussian field marshal (d. 1831) |
| 122759 | October 27 | Birth | 1766 – Nancy Storace, English soprano (d. 1817) |
| 122760 | October 27 | Birth | 1782 – Niccolò Paganini, Italian violinist and composer (d. 1840) |