R-6 was launched at the Fore River Shipbuilding Company, Quincy, Mass, on 1 March 1919. She was placed in commission at Boston on 1 May 1919, with Lieutenant Commander Charles Milford Elder in command.
After fitting out, R-6 was assigned to SubDiv 9 at New London on 16 September 1919. She transfered to Norfolk in December, in order to participate in winter maneuvers in the Gulf of Mexico. She returned to New London in May for four months of summer maneuvers, then sailed for Norfolk for overhaul on 13 September.
SubDiv 9 was ordered to the Pacific in April 1921. R-6 transited the Panama Canal on 28 May, arriving at her new base at San Pedro, California. A malfunction in one of her torpedo tubes caused R-6 to sink in San Pedro Harbor on 26 September 1921. She was refloated on 13 October by Cardinal and R-10 .
In late March and early February 1923, R-6 was used in filming the Twentieth Century-Fox, Buck Jones movie The Eleventh Hour. In July of the same year, R-6 sailed to Hawaii, where she would remain for the next eight years.
Recalled to the Atlantic in December 1930, she arrived in Philadelphia on 9 February 1931 and was decommissioned on 4 May.
Recommissioned 15 November 1940 at New London, R-6 was assigned to SubDiv 42 and sent to Coco Solo. She remained there until 16 June 1941, when she was transfered to SubDiv 31 at St. Thomas, U.S. Virgin Islands. She stayed there until October, when she was sent back to New London for refit.
Following refit, she was assigned anti-U-boat patrol duties, operating between Nantucket and Bermuda. This continued until mid-1943, when she was assigned to training duties. Mostly, this involved training destroyers and destroyer escorts in anti-submarine warfare techniques.
Moving south to Florida in August 1945, her final operations were in the Port Everglades-Key West area. She was decommissioned at Key West on 27 September 1945, and stricken on 11 October. She was sold for scrap in March 1946.
Builder: Fore River
Sponsor: Miss Katherine Langdon Hill
First Captain: LCDR Charles M. Elder
Stricken/Lost: Scrapped 1946