Another Electric Boat contract, built at Fore River Shipbuilding Company, Quincy, MA, R-4 was launched on 26 October 1918 and commissioned under the command of Lieutenant Palmer H. Dunbar on 28 March 1919. She was stationed with SubDiv 9 in New London until 1921, when she was overhauled at Norfolk, then transfered to San Pedro, CA in June. In 1923, R-4 moved with her division to Pearl Harbor, where she remained until December 1930.
For the next ten years, she served as a training boat with SubDiv 4, rotating between the Submarine School and the Yale University NROTC unit.
In May 1941, she reported for patrol duty at Key West. Coming back to New London for the first two weeks in July, she then returned to Key West and alternated between the Fleet Sonar School and patrols in the Florida Straits and Yucatan Channel.
On 11 March 1945, R-4 returned to Key West in preparation for inactivation. Withdrawn from active duty on 1 June, she proceeded to Philadelphia, arriving on the 8th. On 18 June she was decommissioned, and stricken on 11 July. She was sold for scrap in January 1946.
Builder: Fore River
Sponsor: Mrs. A.W. Stahl
First Captain: LT Palmer H. Dunbar, Jr.