Elsmere, DE has a population of 6,137 and is the 5,674th largest city in the United States. The population density is 6,097 per sq mi which is 1556% higher than the Delaware average and 6630% higher than the national average. The median age in Elsmere is 35 which is approximately 11% lower than the Delaware average of 40. In Elsmere, 39% of the population over 15 years of age are married, 77% speak English and 21% speak Spanish. 62% of Elsmere residents were born in Delaware, 26% were born out of state, 1% were born outside of the United States and 11% were foreign born.