State Route 790 (SR 790, OH 790) is an east–west state highway in southeastern Ohio, a U.S. state. Traversing the Wayne National Forest for its duration, State Route 790's western terminus is at State Route 775 in the unincorporated community of Lecta. Its eastern terminus is at State Route 218 about 1 mile (1.6 km) north of the hamlet of Mercerville.

No portion of State Route 790 is included within the National Highway System, a system of highways that are deemed most important for the country's economy, defense and mobility.

State Route 790 came into existence in 1937. When first designated, it was an L-shaped route that began at State Route 217 in Scottown, followed today's Lawrence County Road 37 northerly up to Lecta, ran concurrent with State Route 775 northerly for one block, then turned east to follow its current alignment to State Route 218 near Mercerville. By 1955, the official state transportation map indicated that jurisdiction of the stretch of State Route 790 from Scottown to Lecta had been transferred to Lawrence County, and the highway took on the look that it does today. No other major changes have taken place to the routing of State Route 790 since that time.