The following highways are numbered 618:
| Preceded by 617 | Lists of highways 618 | Succeeded by 619 |
State Route 618 (SR 618) is a 7.45-mile (11.99 km) long east–west state highway in the southeastern quadrant of the U.S. state of Ohio. The western terminus of SR 618 is at an interchange with the concurrency of U.S. Route 50 (US 50), SR 7 and SR 32 about 3.25 miles (5.23 km) west of Belpre. Its eastern terminus is in northern Belpre at an interchange with SR 7.
State Route 339 (SR 339) is a north–south state highway in southeastern Ohio, a U.S. state. The southern terminus of SR 339 is at SR 618 approximately 2 miles (3.2 km) west of Belpre, and less than 0.50 miles (0.80 km) south of the U.S. Route 50 (US 50)/SR 7/SR 32 expressway. The highway's northern terminus is a T-intersection with SR 821 about 0.75 miles (1.21 km) south of Dexter City.
State Route 6 (SR 6) is a state highway that is unsigned. It travels through the central part of the U.S. state of Tennessee from Lawrence County to Sumner County. The highway is related to the following U.S. Highways:
State Route 106 is a north–south state highway in Middle Tennessee. The highway is a secret, or hidden, designation for the following highways:
