Loudoun County, State of Virginia, USA
- Population : 413,538
- Area : 1,336km2
- Website : https://www.loudoun.gov/
- Location : Located at the far north of Virginia. The Potomac river flows from the North of the county and borders with Fairfax County to Southeast.
With its rich soil, it was the fourth largest wheat farm in USA until mid-19th century. However Dallas international airport is located at the south of Loudoun county, so there is a business friendly industry with large scale of business and resident district has developed.
It is one of the 10 counties with the fastest growth for in recent years, and is the best city to live in USA along with Fairfax county in Virginia.