| 8911 | January 21 | Event | 1960 – Avianca Flight 671 crashes and burns upon landing at Montego Bay, Jamaica, killing 37. It is the worst air disaster in Jamaica's history and the first for Avianca. |
| 8912 | January 21 | Event | 1961 – Four hundred thirty-five workers are buried alive when a mine in Coalbrook, Free State collapses. |
| 8913 | January 21 | Event | 1968 – Vietnam War: Battle of Khe Sanh – One of the most publicized and controversial battles of the war begins. |
| 8914 | January 21 | Event | 1968 – A B-52 bomber crashes near Thule Air Base, contaminating the area after its nuclear payload ruptures. One of the four bombs remains unaccounted for after the cleanup operation is complete. |
| 8915 | January 21 | Event | 1971 – The current Emley Moor transmitting station, the tallest free-standing structure in the United Kingdom, begins transmitting UHF broadcasts. |
| 8916 | January 21 | Event | 1976 – Commercial service of Concorde begins with the London-Bahrain and Paris-Rio routes. |
| 8917 | January 21 | Event | 1977 – United States President Jimmy Carter pardons nearly all American Vietnam War draft evaders, some of whom had emigrated to Canada. |
| 8918 | January 21 | Event | 1981 – Production of the iconic DeLorean DMC-12 sports car begins in Dunmurry, Northern Ireland. |
| 8919 | January 21 | Event | 1997 – The U.S. House of Representatives votes 395–28 to reprimand Newt Gingrich for ethics violations, making him the first Speaker of the House to be so disciplined. |
| 8920 | January 21 | Event | 1999 – War on Drugs: In one of the largest drug busts in American history, the United States Coast Guard intercepts a ship with over 4,300 kilograms (9,500 lb) of cocaine on board. |
| 8921 | January 21 | Event | 2000 – Ecuador: After the Ecuadorian Congress is seized by indigenous organizations, Col. Lucio Gutiérrez, Carlos Solorzano and Antonio Vargas depose President Jamil Mahuad. Gutierrez is later replaced by Gen. Carlos Mendoza, who resigns and allows Vice-P |
| 8922 | January 21 | Event | 2003 – A 7.6 magnitude earthquake strikes the Mexican state of Colima, killing 29 and leaving approximately 10,000 people homeless. |
| 8923 | January 21 | Event | 2004 – NASA's MER-A (the Mars Rover Spirit) ceases communication with mission control. The problem lies in the management of its flash memory and is fixed remotely from Earth on February 6. |
| 8924 | January 21 | Event | 2005 – In Belmopan, Belize, the unrest over the government's new taxes erupts into riots. |
| 8925 | January 21 | Birth | 1338 – Charles V of France (d. 1380) |
| 8926 | January 21 | Birth | 1610 – Elizabeth Fones, English-American settler (d. 1673) |
| 8927 | January 21 | Birth | 1721 – James Murray, Scottish-English general and politician Governor of Minorca (d. 1794) |
| 8928 | January 21 | Birth | 1735 – Johann Gottfried Eckard, German pianist and composer (d. 1809) |
| 8929 | January 21 | Birth | 1738 – Ethan Allen, American general (d. 1789) |
| 8930 | January 21 | Birth | 1804 – Eliza R. Snow, American poet and hymn-writer (d. 1887) |
| 8931 | January 21 | Birth | 1813 – John C. Frémont, American general, explorer, and politician, 5th Territorial Governor of Arizona (d. 1890) |
| 8932 | January 21 | Birth | 1815 – John Bingham, American lawyer, judge, and politician, 7th United States Ambassador to Japan (d. 1900) |
| 8933 | January 21 | Birth | 1820 – Joseph Wolf, German ornithologist and illustrator (d. 1899) |
| 8934 | January 21 | Birth | 1824 – Stonewall Jackson, American general (d. 1863) |
| 8935 | January 21 | Birth | 1827 – Ivan Mikheevich Pervushin, Russian mathematician and theorist (d. 1900) |
| 8936 | January 21 | Birth | 1829 – Oscar II of Sweden (d. 1907) |
| 8937 | January 21 | Birth | 1846 – Pieter Hendrik Schoute, Dutch mathematician and academic (d. 1923) |
| 8938 | January 21 | Birth | 1848 – Henri Duparc, French soldier and composer (d. 1933) |
| 8939 | January 21 | Birth | 1860 – Karl Staaff, Swedish lawyer and politician, 11th Prime Minister of Sweden (d. 1915) |
| 8940 | January 21 | Birth | 1864 – Paul Troje, German politician, Mayor of Marburg (d. 1942) |