Luther is a city in Worth Township, Boone County, Iowa, United States. The population was 152 at the time of the 2020 census. It is part of th…Luther is a city in Worth Township, Boone County, Iowa, United States. The population was 152 at the time of the 2020 census. It is part of the Boone, Iowa Micropolitan Statistical Area, which is a part of the larger Ames-Boone, Iowa Combined Statistical Area.