Chattanooga is a city in and the county seat of Hamilton County, Tennessee, United States. It is located along the Tennessee River, and borders Georgia to the south. With a population of 181,099 in 2020, it is Tennessee's fourth-largest city and one of the two principal cities of East Tennessee, along with Knoxville. It anchors the Chattanooga metropolitan area, Tennessee's fourth-largest metropolitan statistical area, as well as a larger three-state area that includes Southeast Tennessee, Northwest Georgia, and Northeast Alabama.