State Route 64 (SR 64) is a 36.44-mile (58.64 km) long north–south state highway in the northwestern portion of the U.S. state of Ohio. The southern terminus of SR 64 is at an interchange with Interstate 75 (I-75) in Bowling Green which also doubles as the western terminus of SR 105. Its northern terminus is at the Michigan state line just 0.25 miles (0.40 km) north of the village limits of Metamora. Continuing north into Michigan's Lenawee County is county-maintained Loar Highway.