USS Dolphin (AGSS-555) was the United States Navy's only operational diesel-electric, deep-diving, research and development submarine. Her keel was laid down on 19 December 1964 at the Portsmouth Navy Yard, Kittery, Maine. She was launched on 6 August 1968 sponsored by Mrs.

USS Dolphin (SF-10/SSC-3/SS-169), a unique submarine and one of the "V-boats," was the sixth ship of the United States Navy to be named for the aquatic mammal. She also bore the name V-7 and the classifications SF-10 and SSC-3 prior to her commissioning. She was launched on 6 March 1932 by the Portsmouth Navy Yard sponsored by Mrs.

Seven ships of the United States Navy have borne the name USS Dolphin, commemorating the dolphin, a gregarious aquatic mammal having a pointed muzzle, and found in most oceans; also, a swift, spiny-finned fish having a long dorsal fin and iridescent body, and found throughout warm seas.