Webster City is a city in Hamilton County, Iowa, United States. The population was 8,070 at the 2010 census. It is the county seat of Hamilton County. Webster City is known as 'Boone River Country', as the Boone River meanders along the east side of the city.
Webster City was originally called Newcastle by settlers. Under the latter name it was changed in 1854 by Wilson Brewer. In 1855, Walter C. Willson came to Newcastle.
Willson was elected to the Iowa State House the next year and, with John F. Duncombe, crafted a bill to divide the very large Webster County in half. Newcastle would be renamed "Webster City," and would become the county seat of the new county. Willson suggested "Hamilton County" after William W. Hamilton, the president of the State Senate.