Onawa was platted in 1857, and the railway arrived to the city in 1867. Onawa was named for a character mentioned in the poem The Song of Hiawatha by Henry Wadsworth Longfellow. It is the largest town on the Iowa side of the Missouri River between Council Bluffs and Sioux City. The population was 2,906 at the time of the 2020 Census. Onawa is a city in, and the county seat of, Monona County, Iowa, United States.
