Niagara Falls, NY has a population of 49,180 and is the 835th largest city in the United States. The population density is 3,491 per sq mi which is 873% higher than the New York average and 3754% higher than the national average. The median age in Niagara Falls is 39 which is approximately 2% higher than the New York average of 38. In Niagara Falls, 46% of the population over 15 years of age are married, 95% speak English and 1% speak Spanish. 82% of Niagara Falls residents were born in New York, 12% were born out of state, 1% were born outside of the United States and 5% were foreign born.