Secaucus, NJ has a population of 18,737 and is the 2,330th largest city in the United States. The population density is 3,216 per sq mi which is 321487% higher than the New Jersey average and 3450% higher than the national average. The median age in Secaucus is 40 which is approximately 1% higher than the New Jersey average of 40. In Secaucus, 61% of the population over 15 years of age are married, 50% speak English and 17% speak Spanish. 43% of Secaucus residents were born in New Jersey, 17% were born out of state, 3% were born outside of the United States and 36% were foreign born.