Herndon is a town in Fairfax County, Virginia, in the Washington, D.C. metropolitan area of the United States. The population was 23,292 at the 2010 census. In 2020, the population was estimated to be 24,532, which makes it the largest of three incorporated towns in the county.The actual dimensions of the town of Herndon are fairly small. However, the United States Post Office treats nearby unincorporated communities in northwestern Fairfax County... Show more

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