SR 140 begins at an intersection with US 80/US 80 Truck/SR 14 Truck/SR 22 Truck/SR 41 just southeast of Selma.

It heads to the east-southeast roughly parallel to the Alabama River.

Near the end of the highway, the river bends away to the east and SR 140 continues to the north.

It ends at an intersection with SR 14 southeast of Burnsville, less than 0.5 miles (0.80 km) from the Autauga County line.

[1] SR 140 was previously created on a route from US 82/SR 6 east of Gordo to US 82/SR 6 in Coker.