Jellico is a city in Campbell County, Tennessee, United States. The population was 2,448 at the 2000 census. The city is situated amidst the Cumberland Mountains in the Elk Creek Valley, which runs perpendicular to the Tennessee-Kentucky state line. Jellico spans the western bases and slopes of three steep hills that split the Elk Creek Valley from the larger Clear Fork Valley to the east. A prominent knob known as Indian Mountain rises nearly 1,000 feet (300 m) above Jellico to the west, and is visible from most of the city. The larger Jellico Mountain dominates the area beyond Indian Mountain to the west, and Pine Mountain dominates the area beyond the Clear Fork Valley to the east.
Jellico is centered around the junction of U.S. Route 25W (North Main Street and 5th Street), which connects Jellico to Interstate 75 to the southeast and Corbin, Kentucky to the north, and Tennessee State Route 97 (South Main Street), which connects Jellico with Huntsville to the southwest. The Tennessee-Kentucky state line forms Jellico's official northern boundary, although houses and businesses associated with the city are on both sides of the border.