State Route 124 or SR-124 is a 10.896-mile (17.535 km) state highway that serves the west, central areas of Walker County. SR-124 intersects SR-118 at its western terminus east of Carbon Hill and SR-69 at its eastern terminus south of Jasper.

State Route 124 begins at its intersection with SR-118 in east of Carbon Hill. From this point, the route travels in a southeasterly direction through Townley. On the eastern side of Townley, SR-124 turns towards the east and continues in an easterly direction to its eastern terminus at SR-69.

The entire route is in Walker County.