Claymont, DE has a population of 8,943 and is the 4,290th largest city in the United States. The population density is 4,159 per sq mi which is 1029% higher than the Delaware average and 4491% higher than the national average. The median age in Claymont is 38 which is approximately 3% lower than the Delaware average of 40. In Claymont, 51% of the population over 15 years of age are married, 92% speak English and 3% speak Spanish. 36% of Claymont residents were born in Delaware, 55% were born out of state, 1% were born outside of the United States and 8% were foreign born.