USS Albacore (AGSS-569) is a unique research submarine that pioneered the American version of the teardrop hull form of modern submarines. The revolutionary design was derived from extensive hydrodynamic and wind tunnel testing, with an emphasis on underwater speed and maneuverability. She was the third vessel of the United States Navy to be named for the albacore.

A teardrop hull is a submarine hull design which emphasizes submerged performance over surfaced performance. It was somewhat commonly used in the early stages of submarine development, but was gradually abandoned in the early 20th century in favour of designs optimized for high performance on the surface as a result of changes in operational doctrine. Although naval doctrine changed, design practices remained until the later parts of World War II when the German Kriegsmarine suffered ever-growing losses of submarines in the Battle of the Atlantic.