County · code 51107
Loudoun CountyVirginia
Loudoun County is a county in Virginia with its seat in Leesburg, formed in 1757. It was named after John Campbell, 4th Earl of Loudoun.
- Founded1757
- County seatLeesburg
- Named forJohn Campbell, 4th Earl of Loudoun
- Land area516 sq mi + 5.6 sq mi water
- Population420,959 2020 Census
- Parcels mapped132,870 checked 15 October 2026
Where it is
Loudoun 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 1757 from Fairfax County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Loudoun County was created from Fairfax County on July 1, 1757. On January 3, 1798, Loudoun County lost territory to Fairfax County.
- 1757
- 1798
- 1998Boundary clarified Boundary between Loudoun and Jefferson (West Virginia) clarified (no change).with Jefferson (W. Va.)no change· Va. Acts 1993, ch. 141/p. 146; Va. Acts 1998, ch. 123/pp. 213-214; W. Va. Acts 1998, ch. 74/pp. 338-339
Land and parcels
What the maps cover in Loudoun
Who publishes each layer, how good it is, and when we last checked.
-
Parcels Good enough
Lot lines and tax-map numbers for 132,870 parcels from Loudoun County. 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, 140,054 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 -
Historic districts Fallback
Published. This copy is a fallback, not the county's own: use it as a guide and check the official record.
-
Plats Good enough
Published.
- 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
Loudoun 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
Email Commissioner of the Revenue
Permits
Zoning and code
County government
- County government
The official website of Loudoun County.
See your own lot on these maps
Open Loudoun 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 Loudoun County
- When was Loudoun County founded?
- Loudoun County was founded in 1757, formed from Fairfax County, and named after John Campbell, 4th Earl of Loudoun.
- What is the county seat of Loudoun County?
- The county seat of Loudoun County is Leesburg.
- Is there an online parcel map for Loudoun County?
- Yes. Loudoun County publishes a parcel map of 132,870 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Loudoun County's boundary or name changed?
- Loudoun County was created in 1757 from Fairfax County. Since then the Atlas of Historical County Boundaries records 1 later change, chiefly involving Fairfax County.
- Who issues building permits in Loudoun County?
- The county's page on building permits: Home Occupation Permit. Inside a city or town, ask that city first.
- Is my lot in a flood zone?
- We do not have flood maps for Loudoun County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby