The Knoxville campaign was a series of American Civil War battles and maneuvers in East Tennessee during the fall of 1863 designed to secure control of the city of Knoxville and with it the railroad that linked the Confederacy east and west, and position the First Corps under Longstreet for return to the Army of Northern Virginia. Union Army forces under Maj. Gen. Ambrose Burnside occupied Knoxville, Tennessee, and Confederate States Army forces under Lt. Gen. James Longstreet were detached from Gen. Braxton Bragg's Army of Tennessee at Chattanooga to prevent Burnside's reinforcement of the besieged Federal forces there. Ultimately, Longstreet's Siege of Knoxville ended when Union Maj. Gen. William Tecumseh Sherman led elements of the Army of the Tennessee and other troops to Burnside's relief after Union troops had broken the Confederate siege of Chattanooga. Although Longstreet was one of Gen. Robert E. Lee's best corps commanders in the East in the Army of Northern Virginia, he was unsuccessful in his attempt to penetrate the Knoxville defenses and take the city.

Knoxville is a city in and the county seat of Knox County, Tennessee, United States. As of the 2020 United States census, Knoxville's population was 190,740, making it 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.