Mondamin is a city in Harrison County, Iowa, United States. The population was 402 at the 2010 census.
Mondamin was platted in the winter of 1867–1868 when the railroad was extended to that point. It was named after Mondamin, a Native American corn deity.
Mondamin is located at 41°42′35″N 96°1′16″W (41.709831, -96.021068).
According to the United States Census Bureau, the city has a total area of 0.45 square miles (1.17 km2), all of it land.
As of the census of 2010, there were 402 people, 175 households, and 122 families living in the city. The population density was 893.3 inhabitants per square mile (344.9/km2). There were 194 housing units at an average density of 431.1 per square mile (166.4/km2). The racial makeup of the city was 97.8% White, 0.2% African American, 0.5% Asian, 0.5% from other races, and 1.0% from two or more races. Hispanic or Latino of any race were 1.0% of the population.
There were 175 households, of which 29.1% had children under the age of 18 living with them, 50.9% were married couples living together, 10.3% had a female householder with no husband present, 8.6% had a male householder with no wife present, and 30.3% were non-families. 26.3% of all households were made up of individuals, and 15.5% had someone living alone who was 65 years of age or older.