Ellsworth is a city in Hamilton County, Iowa, United States. The population was 508 at the time of the 2020 census. Ellsworth was platted in 188…Ellsworth is a city in Hamilton County, Iowa, United States. The population was 508 at the time of the 2020 census. Ellsworth was platted in 1880. It was named to honor the memory of Elmer E. Ellsworth, of the Chicago Zouaves who was murdered in Virginia in the early days of the war of the rebellion.