SR 127 begins in Franklin County in Decherd at an intersection with US 41A/SR 16 at the northern edge of town.

It goes northeast through farmland to have an intersection with SR 279 before crossing the Woods Reservoir/Elk River and entering Coffee County shortly thereafter.

It then leaves Hillsboro and continues northeast through farmland and rural areas along the western edge of the Cumberland Plateau for several miles before crossing into Warren County.

The highway continues northeast through rural areas to enter Viola and become concurrent with SR 108 at the southern edge of town.

SR 127 then curves to the north again to pass through Shellsford and cross a bridge over the Collins River, continuing through farmland and rural areas before coming to an end at an intersection with SR 30, just approximately 1,300 feet east of US 70S.