McKees Rocks, PA has a population of 6,046 and is the 5,737th largest city in the United States. The population density is 5,723 per sq mi which is 1965% higher than the Pennsylvania average and 6216% higher than the national average. The median age in McKees Rocks is 37 which is approximately 8% lower than the Pennsylvania average of 41. In McKees Rocks, 37% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 89% of McKees Rocks residents were born in Pennsylvania, 9% were born out of state, 0% were born outside of the United States and 2% were foreign born.