Johnsonburg, NJ has a population of 84 and is the 27,318th largest city in the United States. The population density is 428 per sq mi which is 42677% higher than the New Jersey average and 372% higher than the national average. The median age in Johnsonburg is 16 which is approximately 61% lower than the New Jersey average of 40. In Johnsonburg, 64% of the population over 15 years of age are married, 54% speak English and 46% speak Spanish. 100% of Johnsonburg residents were born in New Jersey, 0% were born out of state, 0% were born outside of the United States and 0% were foreign born.