fairfax county va population
Population of Fairfax County. Last official estimated population of Fairfax County was 1,086,723 (year 2014)[1]. This was 0.341% of total US population and 13% of total Virginia state population. Area of Fairfax County is 406.1 miÂ² (=1051.7 kmÂ²), in this year population density was 2,676.14 p/miÂ². If population growth rate would be same as in period 2010-2014 (+0.12%/yr), Fairfax County population in 2017 would be 1,090,486 .