Old Black is a mountain in the Great Smoky Mountains, located in the Southeastern United States. While often overshadowed by Mount Guyot, its higher neighbor to the south, Old Black is the 5th-highest mountain in Tennessee and the 7th-highest in the Great Smoky Mountains National Park. The Appalachian Trail crosses its western slope, connecting the Cosby-area trail system with the heart of the Eastern Smokies.