Tennessee (, locally /ˈtɛnəsi/), officially the State of Tennessee, is a state in the southeastern United States. Tennessee is the 36th largest by area and the 16th most populous of the 50 states. It is bordered by eight states, with Kentucky to the north, Virginia to the northeast, North Carolina to the east, Georgia, Alabama, and Mississippi to the south, Arkansas to the west, and Missouri to the northwest. The Appalachian Mountains dominate the eastern part of the state, and the Mississippi River forms its western border. Nashville is the state’s capital and largest city, with a 2019 population of 670,820 and a 2019 metro population of 1,934,317. Tennessee’s second largest city is Memphis, which had a population of 651,073 and metro population of 1,346,045 in 2019.

The state of Tennessee is rooted in the Watauga Association, a 1772 frontier pact generally regarded as the first constitutional government west of the Appalachians. What is now Tennessee was initially part of North Carolina, and later part of the Southwest Territory. Tennessee was admitted to the Union as the 16th state on June 1, 1796. Tennessee was the last state to leave the Union and join the Confederacy at the outbreak of the American Civil War in 1861. Occupied by Union forces from 1862, it was the first state to be readmitted to the Union at the end of the war.

Tennessee furnished more soldiers for the Confederate Army than any other state besides Virginia, and more soldiers for the Union Army than the rest of the Confederacy combined. Beginning during Reconstruction, it had competitive party politics, but a Democratic takeover in the late 1880s resulted in passage of disenfranchisement laws that excluded most blacks and many poor whites from voting. This sharply reduced competition in politics in the state until after passage of civil rights legislation in the mid-20th century. In the 20th century, Tennessee transitioned from an agrarian economy to a more diversified economy, aided by massive federal investment in the Tennessee Valley Authority and, in the early 1940s, the city of Oak Ridge. This city was established just outside of Knoxville to house the Manhattan Project’s uranium enrichment facilities, helping to build the world’s first atomic bombs, two of which were dropped on Imperial Japan near the end of World War II. After the war, the Oak Ridge National Laboratory became and remains a key center for scientific research. In 2016, the element tennessine was named for the state, largely in recognition of the roles played by Oak Ridge, Vanderbilt University, and the University of Tennessee in the element’s discovery.

Tennessee’s major industries include agriculture, manufacturing, and tourism. Poultry, soybeans, and cattle are the state’s primary agricultural products, and major manufacturing exports include chemicals, transportation equipment, and electrical equipment. The Great Smoky Mountains National Park, the nation’s most visited national park, is located in the eastern part of the state, and a section of the Appalachian Trail roughly follows the Tennessee–North Carolina border. Other major tourist attractions include the Tennessee Aquarium and Chattanooga Choo-Choo Hotel in Chattanooga; Dollywood in Pigeon Forge; Ripley’s Aquarium of the Smokies and Ober Gatlinburg in Gatlinburg; the Parthenon, the Country Music Hall of Fame and Museum, and Ryman Auditorium in Nashville; the Jack Daniel’s Distillery in Lynchburg; Elvis Presley’s Graceland residence and tomb, the Memphis Zoo, the National Civil Rights Museum in Memphis; and Bristol Motor Speedway in Bristol.