HMS Sea Devil was a S-class submarine of the third batch built for the Royal Navy during World War II.

Sea Devil had thicker hull plating, which increased her diving depth to 350 feet (106.7 m).

[2] For surface running, the boats were powered by two 950-brake-horsepower (708 kW) diesel engines, each driving one propeller shaft.

[7] In April 1954 Sea Devil deployed to the Mediterranean, and remained there for the rest of her active career.

[6] In 1955–1956 Sea Devil was used around Malta for tests of the Yellow Duckling infrared linescan system for detecting the wake of submerged submarines.