Winneshiek County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 20,070. The county seat is Decorah.

Decorah is a city in and the county seat of Winneshiek County, Iowa, United States. The population was 7,587 at the time of the 2020 census. Decorah is located at the intersection of State Highway 9 and U.S. Route 52, and is the largest community in Winneshiek County.