HMS Calypso (D61) was a C class cruiser of the Caledon sub-class of the Royal Navy, launched in 1917 and sunk in 1940 by the Italian submarine Alpino Bagnolini.

[4][5] Calypso went to the rescue of the Greek royal family in 1922 after King Constantine of Greece abdicated and a military dictatorship seized power.

On 2 November 1924, the destroyer HMS Venomous was steaming in the Grand Harbour upon returning to Valletta, Malta, from a cruise in the Western Mediterranean Sea when she accidentally rammed and sank a motorboat from Calypso.

[7][8] During the early part of the Second World War, Calypso served with the 7th Cruiser Squadron on Northern Patrol duty as a blockade ship in the North Sea between Scotland and Iceland.

Two days after Italy declared war on Great Britain, Calypso was on an anti-shipping patrol against Italian ships travelling to Libya when she was struck by a torpedo from the Italian submarine Alpino Bagnolini (Capitano di corvetta (Lieutenant Commander) Franco Tosoni Pittoni [it]) about 50 mi (80 km) south of Cape Lithion in Crete in the Eastern Mediterranean at 00:59 on 12 June 1940.