Folsom, PA has a population of 8,448 and is the 4,488th largest city in the United States. The population density is 6,759 per sq mi which is 2339% higher than the Pennsylvania average and 7360% higher than the national average. The median age in Folsom is 38 which is approximately 8% lower than the Pennsylvania average of 41. In Folsom, 59% of the population over 15 years of age are married, 89% speak English and 2% speak Spanish. 84% of Folsom residents were born in Pennsylvania, 9% were born out of state, 1% were born outside of the United States and 6% were foreign born.