| County: | Hamilton County |
| State: | Iowa |
| Ex Image: | Hamilton County IA Courthouse.jpg |
| Ex Image Size: | 240px |
| Founded Year: | 1856 |
| Seat Wl: | Webster City |
| Largest City Wl: | Webster City |
| Area Total Sq Mi: | 578 |
| Area Land Sq Mi: | 577 |
| Area Water Sq Mi: | 0.8 |
| Area Percentage: | 0.1 |
| Population As Of: | 2020 |
| Population Total: | 15039 |
| Pop Est As Of: | 2023 |
| Population Est: | 14729 |
| Population Density Sq Mi: | auto |
| Time Zone: | Central |
| Web: | https://www.hamiltoncounty.iowa.gov/ |
| District: | 4th |
Hamilton County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 15,039.[1] The county seat is Webster City.[2] The county was named to honor William W. Hamilton, a President of the Iowa State Senate.[3]
According to the U.S. Census Bureau, the county has a total area of, of which is land and (0.1%) is water.[4] The largest body of water is Little Wall Lake.
The 2020 census recorded a population of 15,039 in the county, with a population density of . 94.75% of the population reported being of one race. There were 7,037 housing units, of which 6,283 were occupied.[1]
| White (NH) | 12,702 | 84.46% | |
| Black or African American (NH) | 88 | 0.6% | |
| Native American (NH) | 25 | 0.16% | |
| Asian (NH) | 314 | 2.1% | |
| Pacific Islander (NH) | 0 | 0% | |
| Other/Mixed (NH) | 445 | 3% | |
| Hispanic or Latino | 1,465 | 9.74% |
The 2010 census recorded a population of 15,673 in the county, with a population density of . There were 7,219 housing units, of which 6,540 were occupied.[6]
As of the census[7] of 2000, there were 16,438 people, 6,692 households, and 4,597 families residing in the county. The population density was 28/mi2. There were 7,082 housing units at an average density of 12/mi2. The racial makeup of the county was 96.71% White, 0.23% Black or African American, 0.20% Native American, 1.46% Asian, 0.01% Pacific Islander, 0.61% from other races, and 0.78% from two or more races. 1.42% of the population were Hispanic or Latino of any race.
There were 6,692 households, out of which 30.60% had children under the age of 18 living with them, 57.90% were married couples living together, 7.60% had a female householder with no husband present, and 31.30% were non-families. 27.50% of all households were made up of individuals, and 13.60% had someone living alone who was 65 years of age or older. The average household size was 2.43 and the average family size was 2.95.
In the county, the population was spread out, with 25.40% under the age of 18, 7.10% from 18 to 24, 27.10% from 25 to 44, 22.40% from 45 to 64, and 18.00% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 98.00 males. For every 100 females age 18 and over, there were 94.80 males.
The median income for a household in the county was $38,658, and the median income for a family was $45,771. Males had a median income of $30,579 versus $23,595 for females. The per capita income for the county was $18,801. About 4.30% of families and 6.30% of the population were below the poverty line, including 7.70% of those under age 18 and 5.50% of those age 65 or over.
Source:[9]
The population ranking of the following table is based on the 2020 census of Hamilton County.[1]
† county seat
| Rank | City/Town/etc. | Municipal type | Population (2020 Census) | |
|---|---|---|---|---|
| 1 | † Webster City | City | 7,825 | |
| 2 | Jewell Junction | City | 1,216 | |
| 3 | Stratford (partially in Webster County) | City | 707 | |
| 4 | Ellsworth | City | 508 | |
| 5 | Stanhope | City | 364 | |
| 6 | Williams | City | 307 | |
| 7 | Kamrar | City | 179 | |
| 8 | Blairsburg | City | 176 | |
| 9 | Randall | City | 154 |
Hamilton County has been a swing county for most of its history. In the last 100 years, it has backed the losing candidate nationally only four times in the 1960, 1988, 2012 and 2020 presidential elections.
School districts include:[10]
Former school districts: