Fairfax County Population 2025

Fairfax County Population 2025. The county’s estimated population is 1,167,000, and we grew by 1.2 percent by the beginning of last year, adding about 14,100 residents. Quickfacts provides statistics for all states and counties.

By 2050, the population is projected to reach 1.38 million. According to the demographic report’s forecasts, the county will hit 1.2 million people by 2025, exceed 1.3 million by 2040, and reach 1.38 million people in 2050.