Four ships of the Royal Navy have been named HMS Parthian, after the ancient Iranic inhabitants of the Parthian Empire. Another was planned but never completed:

• HMS Parthian (1808) was a 10-gun Cherokee-class brig-sloop launched in 1808 and wrecked on the coast of Egypt on 15 May 1828.
• HMS Parthian was to have been a wooden screw gunvessel ordered in 1846, with the order being cancelled in 1849.
• HMS Parthian (1856) was a wooden gunboat launched in 1856 and broken up in 1864.
• HMS Parthian (1916) was an Admiralty M-class destroyer launched in 1916 and sold for scrapping in 1921.
• HMS Parthian (N75) was a Parthian-class submarine launched in 1929, and sunk in 1943.

References

Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.