British 18-inch torpedo

There have been a number of 18-inch (45cm) torpedoes in service with the Royal Navy of the United Kingdom.

These have been used on ships of the Royal Navy and aircraft of both the Fleet Air Arm and Royal Air Force, while Royal Navy surface ships and submarines use 21-inch torpedoes.

The British 18-inch torpedoes were 17.72 inches (45.0 cm) in diameter, beginning with the "Fiume" Whitehead torpedo of 1890.