The area it encompasses was settled in the early 1700s by farmers from Virginia's tidewater region. The Fairfax county courthouse was established at the corner of Old Little River Turnpike (now Main Street) and Ox Road. The small town in the surrounding area was then known as Earp's Corner and in 1805, by an act of the Virginia legislature, named the Town of Providence. People continued to informally refer to it as "Fairfax Court House". The town was officially renamed the Town of Fairfax in 1874. As of the 2000 census, the city had a total population of 21,498. It is the county seat of Fairfax County6.
As of the census of 2000, there are 21,498 people, 8,035 households, and 5,407 families residing in the city. The population density is 1,315.4/km² (3,406.9/mi²). There are 8,204 housing units at an average density of 502.0/km² (1,300.1/mi²). The racial makeup of the city is 72.91% White, 5.07% African American, 0.34% Native American, 12.17% Asian, 0.07% Pacific Islander, 6.17% from other races, and 3.26% from two or more races. 13.64% of the population are Hispanic or Latino of any race.
There are 8,035 households out of which 28.0% have children under the age of 18 living with them, 54.5% are married couples living together, 9.3% have a female householder with no husband present, and 32.7% are non-families. 23.4% of all households are made up of individuals and 6.7% have someone living alone who is 65 years of age or older. The average household size is 2.61 and the average family size is 3.07.
In the city the population is spread out with 20.5% under the age of 18, 9.2% from 18 to 24, 33.7% from 25 to 44, 23.8% from 45 to 64, and 12.8% who are 65 years of age or older. The median age is 37 years. For every 100 females there are 95.2 males. For every 100 females age 18 and over, there are 93.9 males.
The median income for a household in the city is $67,642, and the median income for a family is $78,921. Males have a median income of $50,348 versus $38,351 for females. The per capita income for the city is $31,247. 5.7% of the population and 2.4% of families are below the poverty line. Out of the total people living in poverty, 4.3% are under the age of 18 and 2.1% are 65 or older.