Knoxville is a city in Knox County, Tennessee, United States, and its county seat. It is located on the Tennessee River and had a population of 190,740 at the 2020 United States census. It is the largest city in the East Tennessee Grand Division and the state's third-most populous city, after Nashville and Memphis. It is the principal city of the Knoxville metropolitan area, which had a population of 879,773 in 2020.

First settled in 1786, Knoxville was the first capital of Tennessee. The city struggled with geographic isolation throughout the early 19th century; the arrival of the railroad in 1855 led to an economic boom. The city was bitterly divided over the issue of secession during the American Civil War and was occupied alternately by Confederate and Union armies, culminating in the Battle of Fort Sanders in 1863. Following the war, Knoxville grew rapidly as a major wholesaling and manufacturing center. The city's economy stagnated after the 1920s as the manufacturing sector collapsed, the downtown area declined and city leaders became entrenched in highly partisan political fights. Hosting the 1982 World's Fair helped reinvigorate the city, and revitalization initiatives by city leaders and private developers have had major successes in spurring growth in the city, especially the downtown area.

Knoxville is the home of the flagship campus of the University of Tennessee, whose sports teams, the Tennessee Volunteers, are popular in the surrounding area. Knoxville is also home to the headquarters of the Tennessee Valley Authority, the Tennessee Supreme Court's courthouse for East Tennessee, and the corporate headquarters of several national and regional companies. As one of the largest cities in the Appalachian region, Knoxville has positioned itself in recent years as a repository of Appalachian culture and is one of the gateways to the Great Smoky Mountains National Park.