Seven ships of the United States Navy have borne the name USS Grampus, for two members of the dolphin family (Delphinidae): Grampus griseus, also known as Risso's Dolphin, and Orcinus orca, also known as the orca.

USS Grampus (SS-523), a Tench-class submarine, was the seventh ship of the United States Navy to be named for two members of the dolphin family (Delphinidae): Grampus griseus, also known as Risso's dolphin, and orca, also known as the "Killer Whale." Her keel was laid down on February 8, 1944 at Boston Navy Yard. She was launched on December 16, 1944, but World War II ended before she was completed, and she sat idle until construction resumed in 1948.

USS Grampus (SS-4), a Plunger-class submarine torpedo boat later named A-3, was the fourth ship of the United States Navy to be named for two members of the dolphin family (Delphinidae): Grampus griseus, also known as Risso's dolphin, and Orcinus orca, also known as the killer whale.