Mayville is a city in Dodge County, Wisconsin, United States, located along the Rock River and the Horicon Marsh. The population was 5,154 at t…Mayville is a city in Dodge County, Wisconsin, United States, located along the Rock River and the Horicon Marsh. The population was 5,154 at the 2010 census. Mayville is located at 43°29′49″N 88°32′52″W / 43.49694°N 88.54778°W.