HMS Phoenix was a Parthian-class submarine of the Royal Navy, launched in 1929. She was the eighteenth warship of the Royal Navy to use the name Phoenix. She served on the China Station from her commissioning until the start of the Second World War. Phoenix was then relocated to the Mediterranean Sea and was sunk by the Italian torpedo boat Albatros on 16 July 1940.

HMS Pandora was a British Parthian-class submarine commissioned in 1930 and lost in 1942 during the Second World War. This class was the first to be fitted with Mark VIII torpedoes. On 4 July 1940 she torpedoed and sank the French aviso Rigault de Genouilly off the Algerian coast. In an extension of the Lend-Lease program, Pandora, along with three other British and French submarines, was overhauled at Portsmouth Naval Shipyard in the United States. She was sunk on 1 April 1942 by Junkers Ju 87 aircraft from Sturzkampfgeschwader 3 at the Valletta dockyard, Malta.