Waverly is a city in Bremer County, Iowa, United States. The population was 9,874 at the 2010 census. It is the county seat of Bremer County and is part of the Waterloo–Cedar Falls Metropolitan Statistical Area.The sister city of Waverly is the German city of Eisenach, which is famous for the Wartburg castle. Waverly is also the home of Wartburg College which is named after this castle.