The Italian submarine Delfino was an Italian Italian Squalo-class submarine serving in the Regia Marina during World War II. This was the second unit to bear this name, after the first Delfino of 1892, the ever first italian submarine. This was a unit of the Squalo class, the second of four. Her operative story is developed from the Spanish Civil War to the World War II during which the ship operated always in Mediterranean Sea; she was the protagonist of an episode precurring the Greco-Italian War, the sinking of Greek cruiser Elli in the harbour of Tinos on 15 August 1940.