- September 3 – Ossian Hall is burned by the Annandale Volunteer Fire Department.
- September 10 – 16-year-old Annandale High School student Peter J. Riordan commits suicide in Springfield as part of a pact with Patricia Arcularius.
- September 21 – The Congressional School opens the for the first day of school at its new campus in Falls Church.
- McBee, Susanna, and Jerry Landauer. "Suicide Pact Kills Youth in Fairfax." The Washington Post, Times Herald (1959-1973): A1. ProQuest Historical Newspapers: The Washington Post (1877-1994). Sep 10 1959. Web. 21 Dec. 2011.
|Fairfax County by Year: 1959|
|August 1959||·||September||·||October 1959|