State Route 9 is a north–south route running through four counties in east central Ohio. Its route is 92 miles (148 km) long. The southern terminus is at Route 148 in Armstrongs Mills and the northern terminus is with U.S. Route 62 north of Salem.

This route can prove treacherous to the unsuspecting driver. For much of its length, this road travels along high ledges with many hills, blind corners and hairpin curves.