| 140081 | December 12 | Event | 1984 – Maaouya Ould Sid'Ahmed Taya becomes the third president of Mauritania after a coup d'état against Mohamed Khouna Ould Haidalla while the latter is attending a summit. |
| 140082 | December 12 | Event | 1985 – Arrow Air Flight 1285, a McDonnell Douglas DC-8, crashes after takeoff in Gander, Newfoundland, killing all 256 people on board, including 236 members of the United States Army's 101st Airborne Division. |
| 140083 | December 12 | Event | 1988 – The Clapham Junction rail crash kills thirty-five and injures hundreds after two collisions of three commuter trains—one of the worst train crashes in the United Kingdom. |
| 140084 | December 12 | Event | 1991 – The Russian Federation gains independence from the USSR. |
| 140085 | December 12 | Event | 2000 – The United States Supreme Court releases its decision in Bush v. Gore. |
| 140086 | December 12 | Event | 2001 – Prime Minister of Vietnam Phan Văn Khải announces the decision on upgrading Phong Nha–Kẻ Bàng to the Phong Nha-Kẻ Bàng National Park, providing information on projects for the conservation and development of the park and revised maps. |
| 140087 | December 12 | Event | 2012 – North Korea successfully launches its first satellite, Kwangmyŏngsŏng-3 Unit 2, using an Unha-3 carrier rocket. |
| 140088 | December 12 | Event | 2012 – 12-12-12: The Concert for Sandy Relief took place at Madison Square Garden and was broadcast on 20 international television networks to raise money for the victims of Hurricane Sandy. |
| 140089 | December 12 | Birth | 1298 – Albert II, Duke of Austria (d. 1358) |
| 140090 | December 12 | Birth | 1526 – Álvaro de Bazán, 1st Marquis of Santa Cruz, Spanish admiral (d. 1588) |
| 140091 | December 12 | Birth | 1574 – Anne of Denmark (d. 1619) |
| 140092 | December 12 | Birth | 1610 – Basil of Ostrog, Serbian monk and saint (d. 1671) |
| 140093 | December 12 | Birth | 1685 – Lodovico Giustini, Italian pianist and composer (d. 1743) |
| 140094 | December 12 | Birth | 1712 – Prince Charles Alexander of Lorraine (d. 1780) |
| 140095 | December 12 | Birth | 1715 – Gennaro Manna, Italian composer (d. 1779) |
| 140096 | December 12 | Birth | 1724 – Samuel Hood, 1st Viscount Hood, English admiral and politician (d. 1816) |
| 140097 | December 12 | Birth | 1731 – Erasmus Darwin, English physician and poet (d. 1802) |
| 140098 | December 12 | Birth | 1745 – John Jay, American jurist and politician, 1st Chief Justice of the United States (d. 1829) |
| 140099 | December 12 | Birth | 1766 – Nikolay Karamzin, Russian poet and historian (d. 1826) |
| 140100 | December 12 | Birth | 1779 – Madeleine Sophie Barat, French nun and saint, founded the Society of the Sacred Heart (d. 1865) |
| 140071 | December 12 | Event | 1950 – Paula Ackerman, the first woman appointed to perform rabbinical functions in the United States, leads the congregation in her first services. |
| 140072 | December 12 | Event | 1956 – Beginning of the Irish Republican Army's "Border Campaign". |
| 140073 | December 12 | Event | 1958 – Guinea joins the United Nations. |
| 140074 | December 12 | Event | 1963 – Kenya gains its independence from the United Kingdom. |
| 140075 | December 12 | Event | 1964 – Prime Minister Jomo Kenyatta becomes the first President of the Republic of Kenya. |
| 140076 | December 12 | Event | 1969 – Years of Lead: Piazza Fontana bombing – The offices of Banca Nazionale dell'Agricoltura in Piazza Fontana, Milan, are bombed. |
| 140077 | December 12 | Event | 1979 – Coup d'état of December Twelfth: South Korean Army Major General Chun Doo-hwan orders the arrest of Army Chief of Staff General Jeong Seung-hwa without authorization from President Choi Kyu-ha, alleging involvement in the assassination of ex-Presid |
| 140078 | December 12 | Event | 1979 – President of Pakistan Muhammad Zia-ul-Haq confers Nishan-e-Imtiaz on Nobel laureate Dr Abdus Salam. |
| 140079 | December 12 | Event | 1979 – The unrecognised state of Zimbabwe-Rhodesia returns to British control and resumes using the name Southern Rhodesia. |
| 140080 | December 12 | Event | 1983 – The Australian Labor government led by Prime Minister Bob Hawke and Treasurer Paul Keating floats the Australian dollar. |