State Route 40 (SR 40) is a 30.46-mile-long (49.02 km) state highway in the southeast part of the U.S. state of Georgia. The highway travels from US 1/US 23/US 301/SR 4/SR 15 in Folkston east to Church Street in St. Marys. SR 40 is the primary east–west highway of eastern Charlton County and southern Camden County. The highway connects Folkston and St. Marys with Kingsland, where the highway meets Interstate 95 (I-95) and US 17/SR 25. SR 40 also serves as the majority of the route from I-95 to Naval Submarine Base Kings Bay and Cumberland Island National Seashore. SR 40 has a pair of : a connector route in Folkston and a spur route in St. Marys that provides access to the submarine base and Crooked River State Park.