HMS Myrmidon was an Cormorant-class gunvessel of the Royal Navy, built at the Chatham Dockyard and launched on 5 June 1867. Completed as a survey vessel, she commenced service on the North America and West Indies Station. She commenced service on the Australia Station on 14 March 1885 and undertook hydrographic surveys along the Australian coastline until she left the Australia Station in 1888. She sailed to Hong Kong and was sold in April 1889 for £3000. Her fate is unknown.