Ammon is a suburb city in Bonneville County, Idaho, United States. As of the 2010 US Census, the population of Ammon was 13,816. By the 2020 census, Ammon's population had grown to 17,694. It lies directly to the east of Idaho Falls and to the west of the Ammon foothills, and is the second most populous city in the Idaho Falls metropolitan area. As of 2020, Ammon is the 15th most populous city in Idaho.