- December 7 – 25-year-old Army Specialist Charles R. Harris is fatally shot by 30-year-old Sergeant Leonard L. Malenovsky to settle a dispute between the two soldiers in Ginn's Restaurant in Engleside.
- December 10 – Fairfax County School Board chairman Dr. William S. Hoofnagle is appointed Chairman of the Fairfax County Board of Supervisors by Circuit Court Judge Arthur W. Sinclair.
- December 23 – 12-year-old Patrick J. McCaffrey drowns when he falls through the ice while skating on a pond at the Springfield Country Club in Springfield. His corpse is recovered by divers about two and a half hours later, 15 feet from shore.
- December 24 – On his way to join his wife at a holiday party, 22-year-old Kenneth Ball is killed by 33-year-old Robert C. Plummer when he T-bones Ball's car on Route 50 at Westmoreland Road in Falls Church. Ball is taken to the Fairfax Hospital, where he is pronounced dead.
- "Soldier Arrested in Fatal Shooting." The Washington Post, Times Herald (1959-1973): C4. ProQuest Historical Newspapers: The Washington Post (1877-1995). Dec 09 1969. Web. 7 Feb. 2012.
- Bredemeier, Kenneth. "School Unit's Hoofnagle Named Chairman of Fairfax Supervisors." The Washington Post, Times Herald (1959-1973): A1. ProQuest Historical Newspapers: The Washington Post (1877-1995). Dec 11 1969. Web. 19 Feb. 2012.
- "Boy Is Drowned, Second Skater Saved by Girl" The Evening Star, 24 Dec. 1969, p. B-2. NewsBank. Accessed 27 Aug. 2017.
- "Man Dies on Way to Party." The Washington Post, Times Herald (1959-1973): 1. Dec 26 1969. ProQuest. Web. 9 July 2017.
|Fairfax County by Year: 1969|
|November 1969||·||December||·||January 1970|