USS Shark (SSN-591), a Skipjack-class submarine, was the seventh ship of the United States Navy to be named for the shark.

The Skipjack class was a class of United States Navy nuclear submarines (SSNs) that entered service in 1959-61. This class was named after its lead boat, USS Skipjack. The new class introduced the teardrop hull and the S5W reactor to U.S. nuclear submarines. The Skipjacks were the fastest U.S. nuclear submarines until the Los Angeles-class submarines, the first of which entered service in 1974.