The Sargo class of United States Navy submarine dates from 1939. The submarines had a length of 310.5 feet, with a complement of between 50 and 55 men. They were armed with eight torpedo tubes—4 forward and 4 aft—and one 3" deck gun. They had a top speed of 20 knots surfaced and 7.5 knots submerged. Ten boats of this class were built from 1937 to 1939. They were followed by the Tambor-class submarines.

The Swordfish was the first United States submarine to sink a Japanese ship in World War II.

The Sargo class submarines were

• USS Sargo (SS-188)
• USS Saury (SS-189)
• USS Spearfish (SS-190)
• USS Sculpin (SS-191)
• USS Sailfish (SS-192) (originally named Squalus)
• USS Swordfish (SS-193)
• USS Seadragon (SS-194)
• USS Sealion (SS-195)
• USS Searaven (SS-196)
• USS Seawolf (SS-197)