Columbia, PA has a population of 10,382 and is the 3,841st largest city in the United States. The population density is 4,301 per sq mi which is 1452% higher than the Pennsylvania average and 4647% higher than the national average. The median age in Columbia is 37 which is approximately 9% lower than the Pennsylvania average of 41. In Columbia, 57% of the population over 15 years of age are married, 94% speak English and 4% speak Spanish. 81% of Columbia residents were born in Pennsylvania, 14% were born out of state, 3% were born outside of the United States and 2% were foreign born.