USS Holland (SS-1) was the United States Navy's first modern commissioned submarine, although not the first military submarine of the United States, which was the 1775 submersible Turtle. The boat was originally laid down as Holland VI at the Crescent Shipyard of Elizabeth, New Jersey for John Philip Holland's Holland Torpedo Boat Company, and launched on 17 May 1897. She was acquired by the USN on 11 April 1900 and commissioned on 12 October 1900, Lieutenant H. H. Caldwell commanding.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.