Idaho Falls is the 4th most populous city in Idaho and the county seat of Bonneville County. It is the state's most populous city outside the Boise metropolitan area. As of the 2020 census, the population of Idaho Falls was 64,818. In the 2010 census, the population of Idaho Falls was 56,813, with a metro population of 133,265.Idaho Falls serves as the commercial, cultural, and healthcare hub for Eastern Idaho, as well as parts of western Wyoming and southern Montana.