The median home value in Fairfax County is $539,400. Home values have increased about 3.3% in the past year and are forecast to go up another 3.3% in the next year. The median price per square foot is $305. The median price of homes that are currently listed for sale in Fairfax County is $579,900, while the median sale price is $80,000 less. Cities in Fairfax County include: