Niagara Falls is a city in Niagara County, New York, United States. As of the 2000 census, the city had a total population of 55,593. It is across the Niagara River from Niagara Falls, Ontario (also a city), both named after the famed Niagara Falls which they share. It is part of both the Buffalo - Niagara Falls Metropolitan Statistical Area and the Western New York region.