The USS S-12 was a United States Navy submarine, part of the S-class fleet, commissioned in 1924. Designed for coastal defense, it was equipped with torpedoes and had a displacement of about 1,000 tons when submerged. The submarine was primarily used for training and patrolling during its service. Throughout its operational life, the USS S-12 conducted various exercises and missions, contributing to the development of submarine tactics. It was decommissioned in 1931 and later sold for scrap in 1945, marking the end of its service in the U.S. Navy.