USS O-15 (SS-76) was one of 16 O-class submarines built for the United States Navy during World War I.

[2] For surface running, the boats were powered by two 440-brake-horsepower (328 kW) diesel engines, each driving one propeller shaft.

After the war, she reported to Philadelphia, Pennsylvania, where machinists and electricians worked on her until 20 September 1919, when she was reduced to "in commission, in reserve," at Cape May, New Jersey.

She departed Philadelphia in April 1920 and proceeded, via Jamaica, to Coco Solo, Panama Canal Zone, where she underwent overhaul and conducted experimental tests.

Conducting training cruises, she operated in and around Cuba and the Virgin Islands early in 1922 and returned to Coco Solo in April.