Grundy County, Iowa
Grundy County is a county located in the U.S. state of Iowa. At the 2020 census, the population was 12,329, and was estimated to be 12,361 in 2025. The county seat and the largest city is Grundy Center. The county is named for Felix Grundy, former U.S. Attorney General.
Grundy County is included in the Waterloo–Cedar Falls metropolitan area.