US Highway 127 (US 127) is a part of the United States Numbered Highway System that runs from Chattanooga, Tennessee, to the Lower Peninsula of Michigan. In Ohio, the highway runs 194.27 miles (312.65 km) from the Ohio River in Cincinnati to the Michigan state line north of West Unity. US 127 runs south to north in Ohio's westernmost counties along the border of Indiana. The highway is a main route connecting many small towns, including eight county seats. The highway was first designated in 1926. Its route ended in downtown Toledo before being realigned to its current route in 1930.