Williamsport, PA has a population of 29,180 and is the 1,466th largest city in the United States. The population density is 3,342 per sq mi which is 1106% higher than the Pennsylvania average and 3589% higher than the national average. The median age in Williamsport is 31 which is approximately 23% lower than the Pennsylvania average of 41. In Williamsport, 41% of the population over 15 years of age are married, 95% speak English and 3% speak Spanish. 79% of Williamsport residents were born in Pennsylvania, 19% were born out of state, 1% were born outside of the United States and 2% were foreign born.