Darlington, PA has a population of 271 and is the 22,990th largest city in the United States. The population density is 3,311 per sq mi which is 1095% higher than the Pennsylvania average and 3555% higher than the national average. The median age in Darlington is 34 which is approximately 16% lower than the Pennsylvania average of 41. In Darlington, 44% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 87% of Darlington residents were born in Pennsylvania, 13% were born out of state, 0% were born outside of the United States and 0% were foreign born.