New Seabury, MA has a population of 900 and is the 15,799th largest city in the United States. The population density is 376 per sq mi which is 40% lower than the Massachusetts average and 315% higher than the national average. The median age in New Seabury is 66 which is approximately 67% higher than the Massachusetts average of 39. In New Seabury, 74% of the population over 15 years of age are married, 93% speak English and 3% speak Spanish. 67% of New Seabury residents were born in Massachusetts, 25% were born out of state, 4% were born outside of the United States and 4% were foreign born.