Dahlgren, VA has a population of 3,249 and is the 8,406th largest city in the United States. The population density is 1,214 per sq mi which is 534% higher than the Virginia average and 1240% higher than the national average. The median age in Dahlgren is 32 which is approximately 15% lower than the Virginia average of 38. In Dahlgren, 58% of the population over 15 years of age are married, 93% speak English and 4% speak Spanish. 37% of Dahlgren residents were born in Virginia, 59% were born out of state, 1% were born outside of the United States and 3% were foreign born.