Hamilton Square, NJ has a population of 13,265 and is the 3,148th largest city in the United States. The population density is 3,102 per sq mi which is 310133% higher than the New Jersey average and 3324% higher than the national average. The median age in Hamilton Square is 44 which is approximately 12% higher than the New Jersey average of 40. In Hamilton Square, 64% of the population over 15 years of age are married, 88% speak English and 3% speak Spanish. 71% of Hamilton Square residents were born in New Jersey, 19% were born out of state, 1% were born outside of the United States and 9% were foreign born.