Pietro Calvi was the lead ship of its class of two submarines built for the Regia Marina (Royal Italian Navy) during the 1930s.

The submarine made multiple patrols in the Atlantic Ocean during the Second World War, sinking seven Allied ships.

[1] Pietro Calvi (pennant number CV) was built by Odero-Terni-Orlando at their Muggiano, La Spezia, shipyard.

[1] During the Spanish Civil War, she unsuccessfully fired a pair of torpedoes each at the 6,942-gross register ton (GRT) mail steamer SS Villa de Madrid and the 3946 GRT mail steamer SS Ciudad de Barcelona during a patrol on 1–17 January 1937.

During the sixth patrol from 7 to 29 December Pietro Calvi, Giuseppe Finzi and Enrico Tazzoli rescued sailors of the sunken German commerce raider Atlantis.

[4] Pietro Calvi was rammed and sunk on 14 July by the British sloop HMS Lulworth which was able to briefly board the submarine before she sank.