State Route 77 (SR 77) is a state highway that runs south-to-north through portions of Hancock, Greene, Oglethorpe, Elbert, and Hart counties in eastern Georgia. The route runs from its southern terminus at SR 16 northwest of Sparta to its northern terminus at I-85/SR 403 northeast of Lavonia.

The route initially runs northeast from its southern terminus in Hancock County until it turns north at its intersection with SR 15 north of Sparta, and runs into Greene County co-signed with SR 15. The route goes through White Plains, then splits off SR 15 and crosses I-20 shortly after going through Siloam, and heads north through Union Point and Woodville in Greene County before heading through Maxeys in Oglethorpe County.

SR 77 then turns northeast and heads through Lexington and northeastern Oglethorpe County before turning back north as it crosses into Elbert County and through Elberton into Hart County. Crossing through Hartwell, the route turns slightly northwest and heads towards its northern terminus at I-85.