HMS Arun is the name of two of Royal Navy vessels, named after the English River Arun:

• HMS Arun (1903), a River-class destroyer built by Cammell Laird, Birkenhead, launched in 1903 and completed later that year. The ship was sold for scrap in 1920.
• HMS Arun (M2014), a River-class minesweeper, launched at Lowestoft in 1985. The vessel was sold to the Brazilian Navy in 1998, and renamed successively Hercules, Jose Bonifacio and Babitonga.

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.