County · code 51059
Fairfax CountyVirginia
Fairfax County, Virginia, formed in 1742 from Prince William County, is one of the state's largest counties with its seat in the town of Fairfax.
- Founded1742
- County seatFairfax
- Named forThomas Fairfax
- Land area391 sq mi + 15 sq mi water
- Population1,150,309 2020 Census
- Parcels mapped369,338 checked 15 October 2026
Where it is
Fairfax on the map of Virginia
Virginia has 133 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1742 from Prince William County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Fairfax County was created in 1742 and named after Thomas Fairfax. The county has lost territory over time: in 1757 to the creation of Loudoun County, in 1791 when Virginia ceded land for the federal district, and in 1801 when Alexandria and Arlington counties were created for the federal government's judicial and administrative functions. Further reductions occurred in 1915, 1930, 1948, 1952, and 1961 as Fairfax lost area to the independent cities of Alexandria and Falls Church, and to the independent city of Fairfax.
- 1742
- 1757
- 1791Lost territory Fairfax lost to a newly proclaimed unnamed federal district (now the District of Columbia); Virginia ceded territory to the United States for the seat of the federal government in 1789. Fairfax continued county jurisdiction over the ceded area. · Richardson, 1:102; Van Zandt, 88, 90
- 1798
- 1801Lost territory Fairfax effectively lost to Alexandria (D.C.) the jurisdiction over that part of its territory that had been ceded in 1791 for the seat of the federal government, now called the District of Columbia. · U.S. Stat., vol. 2, ch. 15 [1801]/pp. 103-108; Byron, 1:400-401
Show all 13 changes
- 1742
- 1757
- 1791Lost territory Fairfax lost to a newly proclaimed unnamed federal district (now the District of Columbia); Virginia ceded territory to the United States for the seat of the federal government in 1789. Fairfax continued county jurisdiction over the ceded area. · Richardson, 1:102; Van Zandt, 88, 90
- 1798
- 1801Lost territory Fairfax effectively lost to Alexandria (D.C.) the jurisdiction over that part of its territory that had been ceded in 1791 for the seat of the federal government, now called the District of Columbia. · U.S. Stat., vol. 2, ch. 15 [1801]/pp. 103-108; Byron, 1:400-401
- 1915Lost territory Fairfax lost small area to the independent city of Alexandria. · Bain, Annexation, [240]; Alexandria Planning Dept., correspondence, January 1990
- 1930Lost territory Fairfax lost to the independent city of Alexandria. · Alexandria Planning Dept., correspondence, January 1990; Bain, Annexation, [243]
- 1948Lost territory Fairfax lost to creation of Falls Church as an independent city, 2d class. · Falls Church Public Library, correspondence, March 1990
- 1952Lost territory Fairfax lost to the independent city of Alexandria. · Alexandria Planning Dept., correspondence, January 1990; Bain, Annexation, [245]
- 1961Lost territory Fairfax lost to creation of Fairfax as an independent city, 2d class. · Fairfax Planning Dept., correspondence, February 1990
- c. 1973Lost territory Fairfax lost small area to the independent city of Alexandria. · Alexandria Planning Dept., correspondence, January 1990
- 1980Exchanged territory Fairfax exchanged with the independent city of Fairfax. · Fairfax City Clerk's Office, correspondence, February 1990; U.S. Census Bureau, "Significant Changes to Counties and County Equivalent Entities: 1970-Present," http://www.gov/geo/www/tiger/ctychng.html, 4 August 2003
- 1994Exchanged territory Fairfax exchanged with the independent city of Fairfax. · U.S. Census Bureau, "Geographic Change Notes: Virginia," http://eire.census.gov/popest/geonotes/51.php, 10 June 2003
Land and parcels
What the maps cover in Fairfax
Who publishes each layer, how good it is, and when we last checked.
-
Parcels Good enough
Lot lines and tax-map numbers for 369,338 parcels from Virginia Geographic Information Network (VGIN), Virginia Department of Emergency Management. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 15 October 2026 -
Address points Official
One point per address, 364,026 in all from Virginia Geographic Information Network (VGIN), Virginia Dept of Emergency Management (VDEM; VGIN moved from VITA to VDEM).
checked 14 October 2026 -
Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
Fairfax by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
Who to ask before you build, dig or sell
Official county pages only. We link to them; we do not copy them, because they change.
Inside a city or town, permits usually come from that city rather than the county.
Records
- Assessor and property records
Tax Department Contacts
- Clerk of court: deeds and plats
Permits
Zoning and code
GIS and maps
County government
- County government
The official website of Fairfax County.
See your own lot on these maps
Open Fairfax County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about Fairfax County
- When was Fairfax County founded?
- Fairfax County was founded in 1742, formed from Prince William County, and named after Thomas Fairfax.
- What is the county seat of Fairfax County?
- The county seat of Fairfax County is Fairfax.
- Is there an online parcel map for Fairfax County?
- Yes. Virginia Geographic Information Network (VGIN), Virginia Department of Emergency Management publishes a parcel map of 369,338 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Fairfax County's boundary or name changed?
- Fairfax County was created in 1742 from Prince William County. Since then the Atlas of Historical County Boundaries records 12 later changes, chiefly involving Loudoun County and Alexandria (D.C.) County.
- Who issues building permits in Fairfax County?
- The county's page on building permits: Park Use Permits. Inside a city or town, ask that city first.
- Who issues septic and well permits in Fairfax County?
- The county's page on septic systems and wells: Contact Us.
- Is my lot in a flood zone?
- We do not have flood maps for Fairfax County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby