Knoxville, PA has a population of 698 and is the 17,498th largest city in the United States. The population density is 1,125 per sq mi which is 306% higher than the Pennsylvania average and 1142% higher than the national average. The median age in Knoxville is 36 which is approximately 11% lower than the Pennsylvania average of 41. In Knoxville, 55% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 70% of Knoxville residents were born in Pennsylvania, 29% were born out of state, 1% were born outside of the United States and 0% were foreign born.