State Route 105 (SR 105) is an east–west state highway in the northwestern portion of the U.S. state of Ohio. Its western terminus is at an interchange with Interstate 75 in Bowling Green that doubles as the southern terminus of State Route 64, and its eastern terminus is at State Route 19 in Oak Harbor. For its final 0.4 miles (0.64 km), the route overlaps State Route 163 which continues east.