HMS Syrtis was a third-batch S-class submarine built for the Royal Navy during the Second World War.

Syrtis was then assigned to take part in Operation Source, an attack on the German battleships based in Norway, using midget submarines.

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

[5] HMS Syrtis was a third-batch S-class submarine ordered by the British Admiralty on 25 January 1941.

[1] On 21 April Syrtis, under the command of Lieutenant Michael Hugh Jupp, sailed to Holy Loch, where she was commissioned into the Royal Navy two days later.

[7] After training off several British coastal cities, Syrtis commenced an anti-submarine patrol off Norway on 6 July 1943.

On 11 September 1943, the boat departed port towing the X-class submarine X9 close to her target, the battleship Scharnhorst.

[6] On 2 February 1944, Syrtis departed Kames Bay with the X-class midget submarine X22 in tow.

Five days later, while nearing Scapa Flow, Syrtis's watch officer was washed overboard; the submarine turned to pick him up, but collided with X22, which went down with all hands.

She achieved the only success of her career on 22 March, sinking the Norwegian merchant Narvik with gunfire off Rødøya.

German reports indicate the sinking of a submarine in the Bodø area at the time by shore batteries, but the most likely cause of her loss is a mine.