State Route 101 (SR 101) is a southwest-northeast (signed east–west) state highway in the north central portion of the U.S. state of Ohio. Its western terminus is at the junction of State Route 53 and State Route 18 in Tiffin; it runs concurrently with State Route 18 for about 1 mile (1.6 km). Its eastern terminus is at the junction of U.S. Route 6 and State Route 4 in Sandusky; it runs concurrently with U.S. Route 6 for just over 1½ miles to its western terminus.