State Route 251 (SR 251) is a southeast-northwest state highway located in the east-central part of the U.S. state of Georgia. Its route runs for approximately 13.5 miles (21.7 km) entirely within McIntosh County.

SR 251 begins at an intersection with US 17/SR 25 in Darien. Here, the roadway continues as Dunbar Street. The route heads northwest, passing the Darien Inland Harbor Campground. It then has an interchange with Interstate 95 (I-95, unsigned SR 405) northwest of the city. Just past I-95 is access to the Preferred Outlets at Darien, an outlet mall. The highway then turns north, running through rural portions of the county, until it meets its northern terminus, an intersection with SR 57 in Townsend. Here, the roadway continues as Old Townsend Road.

No section of SR 251 is part of the National Highway System, a system of routes determined to be the most important for the nation's economy, mobility and defense.

SR 251 was established in 1949 along an alignment from its current southern terminus north-northwest and then northwest of the city, to what is now the unincorporated community of Cox. In 1955, a short section from Darien to northwest of I-95 was paved. By 1963, the road's entire route was paved. By 1979, the road was moved to, and paved along its current alignment.

The entire route is in McIntosh County.