Rockwell is a city in Cerro Gordo County, Iowa, United States. The population was 1,071 at the time of the 2020 census. In 2020, it was …Rockwell is a city in Cerro Gordo County, Iowa, United States. The population was 1,071 at the time of the 2020 census. In 2020, it was speculated that the city is part of the Mason City Micropolitan Statistical Area.