Niagara is a city in Marinette County, Wisconsin, United States. The population was 1,880 at the 2000 census. The city lies to the north of and adjacent to the Town of Niagara. It is part of the Marinette, WI–MI Micropolitan Statistical Area.
The city of Niagara was founded in 1900 on the banks of the Menominee River. Niagara is an Iroquois word that means "thundering waters", which is also used in the famous Niagara Falls, between New York and the Canadian province of Ontario.
On July 31, 2008 a gunman fatally shot three teenagers swimming in the Menominee River near Niagara. Scott J. Johnson of Kingsford, Michigan was arrested and charged with the crimes. In March of 2009 Johnson pleaded no contest to ten felonies including three homicides and is scheduled to be sentenced May 21.