HMS Fly (J306) was a reciprocating engine-powered Algerine-class minesweeper during the Second World War.

The engines produced a total of 2,400 indicated horsepower (1,800 kW) and gave a maximum speed of 16.5 knots (30.6 km/h; 19.0 mph).

They carried a maximum of 660 long tons (671 t) of fuel oil that gave them a range of 5,000 nautical miles (9,300 km; 5,800 mi) at 10 knots (19 km/h; 12 mph).

The latter guns were in short supply when the first ships were being completed and they often got a proportion of single mounts.

The flotilla was dispatched to sweep the mine fields off the French, Dutch coast and islands.