Seven ships of the Royal Navy have been named HMS Sirius after the brightest star in the night sky.

• HMS Sirius (1786) was the flagship of the First Fleet to Australia.
• HMS Sirius (1797) was a 36-gun fifth-rate frigate, and served during the Napoleonic Wars until she was lost at the Battle of Grand Port, Isle de France.
• HMS Sirius (1813) was a fifth-rate frigate. She was never commissioned and apparently spent her whole career at Portsmouth in ordinary until she was broken up there in 1862.
• HMS Sirius (1868) was an Eclipse-class wooden screw sloop sold in 1885.
• HMS Sirius (1890) was an Apollo-class protected cruiser that served in World War I.
• HMS Sirius (82) was a Dido-class light cruiser in World War II.
• HMS Sirius (F40) was a Leander-class frigate in service until 1994.
• SS Sirius (1837)

• HMAS Sirius (O 266) - Royal Australian Navy replenishment vessel, named in honour of First Fleet ship HMS Sirius (1786).

List of ships with the same or similar names

This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.