|Laid down||30 June 1928|
|Launched||22 June 1929|
|Commissioned||13 January 1931|
|Identification||Pennant number N75|
|Fate||Sunk in the Mediterranean Sea between 28 July and 11 August 1943|
|Class and type||Parthian-class submarine|
|Length||260 ft (79 m)|
|Beam||28 ft (8.5 m)|
|Draught||13 ft 8 in (4.17 m)|
|Range||8,500 nmi (15,700 km) at 10 kn (12 mph; 19 km/h)|
HMS Parthian was the lead boat of the six Royal Navy Parthian-class submarines, all launched in 1929. The submarine was sunk in 1943 during the Second World War. The submarine was nicknamed Peanut, from the identity letters PN painted on the fin.
Parthian spent most of her Second World War service in the Mediterranean. On the outbreak of the war, she was on the China Station, but was transferred to Alexandria in May 1940. She sank the Italian submarine Diamante near Tobruk on 20 June 1940. By the end of the year she had been attached to the 8th Submarine Flotilla based at Malta.
She also sank the Vichy French submarine Souffleur off Beirut on 25 June 1941, during the combined British/Free French campaign to occupy Syria and Lebanon. Parthian underwent a refit in the United States from late 1941 until March 1942 before returning to the Mediterranean, where she carried out supply operations between July and October to Malta carrying aviation fuel and ammunition. To increase her cargo capacity, one of the batteries was removed and no spare torpedoes were carried. In May 1943 the submarine sank a number of Italian sailing vessels in the Aegean Sea.
The submarine left Malta on 22 July 1943 for a patrol in the southern Adriatic. She was diverted to a patrol area off Otranto on 26 July, and diverted again on 28 July. The submarine was signalled on 6 August to leave the patrol area but the signal was not acknowledged. Parthian failed to arrive at Beirut, where she was due on 11 August. It is likely that she was sunk by a naval mine near Brindisi.
One crewmember lost with Parthian was Timothy Walker, the son of Captain Frederic John "Johnny" Walker, a leading U-boat hunter.
- Playfair, Vol. I, page 110.
- Caruana, Joseph (2012). "Emergency Victualling of Malta During WWII". Warship International. LXIX (4): 357–364. ISSN 0043-0374.
- "HMS Parthian (N 75)". Uboat.net. Retrieved 1 December 2006.
- "HMS Parthian". RN Subs. Retrieved 27 September 2022.
- "The HMS Parthian P-class British submarine off Brindisi 1943". Abysso. Archived from the original on 11 May 2006. Retrieved 1 December 2006.
- Playfair, Major-General I.S.O.; Molony, Brigadier C.J.C.; with Flynn, Captain F.C. (R.N.) & Gleave, Group Captain T.P. (2009) [1st. pub. HMSO:1954]. Butler, Sir James (ed.). The Mediterranean and Middle East, Volume I: The Early Successes Against Italy, to May 1941. History of the Second World War, United Kingdom Military Series. Uckfield, UK: Naval & Military Press. ISBN 978-1-84574-065-8.
- Media related to HMS Parthian (N75) at Wikimedia Commons