HMS Sterlet was a second-batch S-class submarine built during the 1930s for the Royal Navy.

The second batch of S-class submarines were designed as slightly improved and enlarged versions of the earlier boats of the class and were intended to operate in the North and Baltic Seas.

[3] For surface running, the boats were powered by two 775-brake-horsepower (578 kW) diesel engines, each driving one propeller shaft.

[2] Ordered on 2 March 1936, Sterlet was laid down on 14 July 1936 in HM Dockyard, Chatham and was launched on 22 September 1936.

[6] On 8 April 1940 Sterlet left for a patrol in the Skagerrak, off Norway under the command of Lt. Gerard Henry Stacpoole Haward.