USS Hammerhead (SS-364), a Gato-class submarine, was the first ship of the United States Navy to be named for the hammerhead shark, a shark found in warm seas with a flattened anterior forward of the gill slits, presenting a hammer-like silhouette when viewed from above.

The Gato class of submarines were built for the United States Navy and launched in 1941–1943. Named after the lead ship of the class, USS Gato, they were the first mass-production U.S. submarine class of World War II.