Marinette is a city in and the county seat of Marinette County, Wisconsin, United States. It is located on the south bank of the Menominee Riveā¦Marinette is a city in and the county seat of Marinette County, Wisconsin, United States. It is located on the south bank of the Menominee River, at its mouth at Green Bay, part of Lake Michigan; to the north is Stephenson Island, part of the city preserved as park. During the lumbering boom of the late 19th century, Marinette became the tenth-largest city in Wisconsin in 1900, reaching a peak population of 16,195.