Two ships of the United States Navy have borne the name USS Harder, named in honor of the harder, a fish of the mullet family found off South Africa.
- USS Harder (SS-257), was a Gato-class submarine, commissioned in 1942 and sunk in 1944. The vessel's wreck was found in 2024.
- USS Harder (SS-568), was a Tang-class submarine, commissioned in 1952 and struck in 1974
This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.