State Route 266 is a state highway in Middle Tennessee. The southern terminus is in a currently undeveloped section of Smyrna at an interchange with I-24. The northern terminus is in Lebanon at an intersection with US 70.

Interstate 24 (I-24) is an Interstate Highway in the Midwestern and Southeastern United States. It runs diagonally from I-57, 10 miles (16 km) south of Marion, Illinois, to Chattanooga, Tennessee, at I-75. It travels through Illinois, Kentucky, Tennessee, and Georgia. As an even-numbered Interstate, it is signed as an east–west route, though the route follows a more southeast–northwest routing, passing through Nashville, Tennessee. The numbering deviates from the standard Interstate Highway System grid, lying further north than its number would indicate west of Nashville. The short segment within Georgia bears the unsigned designation State Route 409 (SR 409).