Plano is a city in Appanoose County, Iowa, United States. The population was 59 at the time of the 2020 census. Plano was incorporated in 19…Plano is a city in Appanoose County, Iowa, United States. The population was 59 at the time of the 2020 census. Plano was incorporated in 1916. A large portion of the early settlers being natives of Plano, Illinois, caused the name to be selected.