Four ships of the Royal Navy have been named HMS Louisa:

• HMS Louisa (1794) was a 3-gun gunvessel, previously a hoy, purchased in 1794 and sold in 1798.
• HMS Louisa was also a 3-gun vessel, separate from the above, purchased in 1798 and sold in 1799.^[1]
• HMS Louisa (1814) was a tender in service in 1814 and sold in 1816.
• HMS Louisa (1834) was a cutter purchased in 1834. She foundered in 1841.
• HMS Louisa (1855) was an Albacore-class wooden screw gunboat launched in 1855 and sold in 1867.

• HM Hired armed brig Louisa
• HM Hired tender Louisa
• HMS Louis
• HMS Princess Louisa
• USS Louise

• 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.
• Winfield, Rif (2008). British Warships in the Age of Sail 1793–1817: Design, Construction, Careers and Fates. Seaforth. ISBN 978-1-86176-246-7.