The USS O-5 was a submarine of the United States Navy, part of the O-class submarines. Launched in 1918, it was designed for coastal defense and had a displacement of about 1,000 tons when submerged. The submarine was equipped with torpedoes and had a crew of around 30 men. During its service, the USS O-5 operated primarily in the Atlantic Ocean. It was notable for being involved in various training exercises and patrols. The submarine was decommissioned in 1924 and later sold for scrap in 1931, marking the end of its operational life.