December 3 - The Warren Commission begins its investigation into the assassination of John F. Kennedy.

December 4 - The second period of the Second Vatican Council closes.

December 5 - The Seliger Forschungs-und-Entwicklungsgesellschaft mbH demonstrates rockets for military use to military representatives of non-NATO-countries near Cuxhaven. Although these rockets land via parachute at the end of their flight and no allied laws are violated, the Soviet Union protests this action.

December 7 - Tony Verna, a CBS-TV director, debuts an improved version of instant replay during his direction of a live televised sporting event, the Army-Navy Game of college football played in Philadelphia. This instance is notable as it was the first instant replay system to use videotape instead of film.

December 8 - A lightning strike causes the crashing of Pan Am Flight 214 near Elkton, Maryland, killing 81 people. - Frank Sinatra, Jr. is kidnapped at Harrah's Lake Tahoe.

December 10 - In the United States, the X-20 Dyna-Soar spaceplane program is cancelled. - Chuck Yeager narrowly escapes death while testing an NF-104A rocket-augmented aerospace trainer when his aircraft goes out of control at 108,700 feet (nearly 21 miles up) and crashed. He parachutes to safety at 8,500 feet after vainly battling to gain control of the powerless, rapidly falling craft. In this incident he becomes the first pilot to make an emergency ejection in the full pressure suit needed for high altitude flights.

December 12 - Kenya gains independence from the United Kingdom, with Jomo Kenyatta as prime minister.

December 19 - Zanzibar gains independence from the United Kingdom, as a constitutional monarchy under Sultan Jamshid bin Abdullah.

December 21 - Cyprus Emergency: Inter-communal fighting erupts between Greek and Turkish Cypriots.

December 22 - The cruise ship Lakonia burns 180 miles (290 km) north of Madeira, with the loss of 128 lives.

December 25 - Walt Disney releases his 18th feature-length animated motion picture The Sword in the Stone, about the boyhood of King Arthur. It is the penultimate animated film personally supervised by Disney. - I.smet I.nönü of the Republican People's Party (CHP) forms the new government of Turkey (28th government, coalition partners; independents, I.nönü has served 10 ten times as a prime minister, this is his last government).

December 26 - The Beatles' "I Want to Hold Your Hand" and "I Saw Her Standing There" are released in the United States, marking the beginning of Beatlemania on an international level. (source: Wikipedia)