HMS Fly (1776) was a 14-gun sloop launched in 1776 and foundered off the Newfoundland coast in 1801 or 1802.
HMS Fly (1778) was a 14-gun cutter purchased in 1780 and captured by the French in May 1781.
HMS Fly (1804) was an 18-gun sloop launched in 1804 and wrecked in March 1805 on the Carysfort Reef in the Gulf of Florida; her crew were saved.
HMS Fly (1805) was a 16-gun brig-sloop launched in 1805. In 1807 she participated in one major naval campaign. She was wrecked on 28 February 1812 at Anholt Island in the Kattegat.
HMS Fly (1831) was an 18-gun sloop launched in 1831. She was converted into a coal hulk in 1855, after which she was renamed C2 and then C70. She was broken up in 1903.
HMS Fly (J306) was an Algerine-classminesweeper launched in 1942. She was sold to Iran in 1949 and renamed Palang. She was paid off in 1966 and stricken from the navy list in 1972. She sank and was then broken up.