Millville, DE has a population of 1,611 and is the 12,298th largest city in the United States. The population density is 643 per sq mi which is 75% higher than the Delaware average and 610% higher than the national average. The median age in Millville is 42 which is approximately 5% higher than the Delaware average of 40. In Millville, 55% of the population over 15 years of age are married, 90% speak English and 4% speak Spanish. 26% of Millville residents were born in Delaware, 66% were born out of state, 0% were born outside of the United States and 8% were foreign born.