State Route 27 is part of Maine's system of numbered state highways, running 154.1 miles (248.0 km) from the village of Newagen in Southport at SR 238 to the Coburn Gore–Woburn Border Crossing, where it continues into Quebec as Route 161.

Southport is a town and archipelago in Lincoln County, Maine, United States. The population was 622 at the 2020 census. It includes the neighborhoods of Capitol Island, Cozy Harbor, East Side, Newagen, Pine Cliff, and West Southport, and the village of Squirrel Island. The majority of the town's residents live on its main island, Southport Island.