Hamilton County, Iowa

Hamilton County, Iowa
The Hamilton County Courthouse in Webster City
Location within the U.S. state of Iowa
Coordinates: 42°23′27″N 93°42′33″W / 42.390789°N 93.709130°W / 42.390789; -93.709130
Country United States
State Iowa
FoundedJanuary 8, 1857
Named afterWilliam W. Hamilton
SeatWebster City
Largest cityWebster City
Area
 • Total
577.486 sq mi (1,495.68 km2)
 • Land576.731 sq mi (1,493.73 km2)
 • Water0.755 sq mi (1.96 km2)  0.13%
Population
 (2020)
 • Total
15,039
 • Estimate 
(2024)
14,856
 • Density26.076/sq mi (10.068/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Area code515
Congressional district4th
Websitehamiltoncounty.iowa.gov
  • Iowa county number 40

Hamilton County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 15,039, and was estimated to be 14,856 in 2024. The county seat and the largest city is Webster City. The county was named to honor William W. Hamilton, a President of the Iowa State Senate.