USS Canopus (AS-9) was a submarine tender in the United States Navy, named for the star Canopus. Canopus was launched in 1919 by New York Shipbuilding Company, Camden, New Jersey, as the passenger liner SS Santa Leonora for W. R. Grace and Company, but taken over by the U.S. Navy upon completion in July 1919 and commissioned as USS Santa Leonora. She was briefly employed as a trans-Atlantic troop transport before being decommissioned and transferred to the U.S. Army in September 1919.