I-19 was a Japanese Type B1 submarine which damaged and destroyed several enemy ships during World War II while serving in the Imperial Japanese Navy. During the Guadalcanal Campaign, with a single torpedo salvo, the submarine sank the aircraft carrier USS Wasp and the destroyer USS O'Brien and damaged the battleship USS North Carolina.

The Type B1 submarine , also called I-15-class submarine was the first group of boats of the Type B cruiser submarines built for the Imperial Japanese Navy (IJN) during the 1940s. In total 20 were built, starting with I-15, which gave the series their alternative name.