North Tonawanda is a city in Niagara County, New York, United States. The population was 31,568 at the 2010 census. It is part of the Buffalo–Niagara Falls Metropolitan Statistical Area. The city is named after Tonawanda Creek, its south border. Tonawanda in the Seneca tongue means "Swift Running Water". Tonawanda Creek, which flows into the Niagara River, once had large stretches of rapids (see Rapids, New York) until it was tamed with the construction of the Erie Canal.