Phillipsburg, NJ has a population of 14,570 and is the 2,901st largest city in the United States. The population density is 4,567 per sq mi which is 456551% higher than the New Jersey average and 4940% higher than the national average. The median age in Phillipsburg is 40 which is approximately 1% higher than the New Jersey average of 40. In Phillipsburg, 53% of the population over 15 years of age are married, 86% speak English and 9% speak Spanish. 57% of Phillipsburg residents were born in New Jersey, 31% were born out of state, 1% were born outside of the United States and 11% were foreign born.