USS Hyac (SP-216) was a United States Navy patrol vessel in commission from 1917 to 1918. Hyac was built as a civilian motorboat of the same name in 1915 by the Weckler Boat Company at Chicago, Illinois. The U.S. Navy acquired her from her owner, W. M. Derby of Chicago, in 1917 for World War I service as a patrol vessel. She was commissioned as USS Hyac (SP-216) on 5 July 1917 with Lieutenant W. M. Derby in command. Following the end of the war, Hyac was returned to her owner on 26 November 1918.