Resident Population in Arlington County, VA was 239.80700 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Arlington County, VA reached a record high of 239.80700 in January of 2024 and a record low of 152.59900 in January of 1980. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Arlington County, VA - last updated from the United States Federal Reserve on April of 2026.