Manassas, VA has a population of 41,149 and is the 998th largest city in the United States. The population density is 4,178 per sq mi which is 2083% higher than the Virginia average and 4512% higher than the national average. The median age in Manassas is 33 which is approximately 12% lower than the Virginia average of 38. In Manassas, 59% of the population over 15 years of age are married, 60% speak English and 31% speak Spanish. 41% of Manassas residents were born in Virginia, 29% were born out of state, 2% were born outside of the United States and 28% were foreign born.