Dickinson County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 17,703. The county seat is Spirit Lake. The county was organized in 1857 and is named in honor of Daniel S. Dickinson, a U.S. Senator for New York.

Spirit Lake is a city in Dickinson County, Iowa, United States. The population was 5,439 at the 2020 census. It is the county seat of Dickinson County.