Logan is a city in Cache County, Utah, United States. The 2010 census recorded the population was 48,174, with an estimated population of 51,542 in 2018. By 2050 the population of Logan is expected to double. 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 125,442 people as of the 2010 census and was declared by Morgan Quitno in 2005 and 2007 to be the safest in the United States in those years. Logan also is the location of the main campus of Utah State University.