Logan is a city in Cache County, Utah, United States. The 2020 census recorded the population was 52,778. Logan is the county seat of Cac…Logan is a city in Cache County, Utah, United States. The 2020 census recorded the population was 52,778. Logan is the county seat of Cache County and the principal city of the Logan metropolitan area, which includes Cache County and Franklin County, Idaho. The Logan metropolitan area contained 147,908 people as of the 2020 census. Logan is the location of the main campus of Utah State University.