Mellen is a city in Ashland County in the U.S. state of Wisconsin. The population was 698 at the 2020 census. Mellen has a mayor-council f…Mellen is a city in Ashland County in the U.S. state of Wisconsin. The population was 698 at the 2020 census. Mellen has a mayor-council form of government. According to the Mellen Weekly-Record; Vol.123 No. 29; Wednesday, July 20, 2022, Mayor Joseph A. Barabe, resigned effective at noon, on July 15, 2022. No further explanation was given. Nathaniel Delegan, President of the Mellen City Council, served as Acting Mayor until the election of a new Mayor on April 4, 2023.