Gibson is a city in Keokuk County, Iowa, United States. The population was 63 at the time of the 2020 census. According to the United Stateā¦Gibson is a city in Keokuk County, Iowa, United States. The population was 63 at the time of the 2020 census. According to the United States Census Bureau, the city has a total area of 0.07 square miles, all of it land.