SR 55 begins at an intersection with SR 37/SR 62 in Leary, in Calhoun County. It heads northeast on Mercer Avenue, before traveling to the north on Bray Street. It travels northeast, through rural sections of the county. The highway passes the Spring Creek Cemetery. Just over 1 mile (1.6 km) after intersecting SR 234, the route crosses into Terrell County. The highway continues to the north until it meets its northern terminus, an intersection with US 82/SR 520 in Dawson.
A largely rural route, State Route 55 sees an Average Annual Daily Traffic of less than 2,000 vehicles.
SR 55 is not part of the National Highway System, a system of roadways important to the nation's economy, defense, and mobility.