The USS S-20 was a United States Navy submarine, part of the S-class fleet, launched on March 1, 1923. 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-20 was stationed in various locations, including the Atlantic and Pacific Oceans. It was decommissioned on June 30, 1931, and later sold for scrap in 1934. The S-class submarines, including the S-20, played a significant role in the development of submarine technology during the early 20th century.