The second USS Grampus was a side-wheel steamer in the United States Navy. She was named for a member of the dolphin family (Delphinidae): Grampus griseus, also known as Risso's Dolphin. Originally named Ion, she was purchased by Rear Admiral David D. Porter for the U.S. Navy on 22 July 1863, at Cincinnati, Ohio, for US$9750. She was stationed at Cincinnati, Ohio, and used as a receiving ship for the Mississippi Squadron. By 14 November 1863, with Acting Master Elijah Sells in command, she was recognized as a "nice little receiving vessel in first-rate order," but contained no furnishings or weapons other than ten cutlasses and revolvers.