Horicon is a city in Dodge County, Wisconsin, United States. The population was 3,655 at the 2010 census. Horicon is located at 43°27…Horicon is a city in Dodge County, Wisconsin, United States. The population was 3,655 at the 2010 census. Horicon is located at 43°27′N 88°39′W / 43.450°N 88.650°W. According to the United States Census Bureau, the city has a total area of 3.42 square miles, of which, 3.21 square miles is land and 0.21 square miles is water.