Tennessee State Route 33 is a primary and secondary route in the U.S. state of Tennessee. It runs 176 miles, from the Georgia state line in Polk County, northeast to the Virginia state line north of Kyles Ford in Hancock County. South of Maryville, SR-33 is a "hidden" route which shares a concurrency with US 411.

The section of SR-33 between Knoxville and Tazewell, along with US 25E between Tazewell and Middlesboro, KY, was an inspiration for the song The Ballad of Thunder Road. In the song, a moonshiner runs illegal whiskey from Kentucky to Knoxville on this route. Sections of old highway 33 in Union County have signs marking "The Original Thunder Road".