The Groton and Stonington Street Railway was an interurban trolley line that extended from Groton, Connecticut, to Westerly, Rhode Island, with a later branch to Old Mystic, Connecticut, and an extension to New London.

The Groton and Stonington Street Railway was chartered on August 17, 1903, with permission to build two lines.

[1] The G&S opened from Groton to Mystic on December 19, 1904, to Stonington on April 8, 1905, and finally to the state line at Westerly on May 6, 1905.

[1] The trolley line started at Thames Street in Groton, passing through Poquonnock and Noank, and ending in Mystic.

[2] The adjacent carhouse was retrofitted with two additional stories in the 1980s and converted into condominiums as well.