Niagara, WI has a population of 1,610 and is the 12,300th largest city in the United States. The population density is 583 per sq mi which is 567% higher than the Wisconsin average and 543% higher than the national average. The median age in Niagara is 37 which is approximately 5% lower than the Wisconsin average of 39. In Niagara, 52% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 25% of Niagara residents were born in Wisconsin, 72% were born out of state, 1% were born outside of the United States and 1% were foreign born.