Ida County is a county located in the U.S. state of Iowa. As of the 2020 census the population was 7,005, making it the state's eighth-least populous county. The county seat is Ida Grove. The county was authorized by the Iowa Legislature in January 1851 as a packet of projected counties in unorganized territory of western Iowa. It was named after Ida Smith, the first child of European immigrants to be born in this region.

Ida Grove is a city in Ida County, Iowa, United States. The population was 2,051 at the time of the 2020 census. It is the county seat of Ida County.