The 4.7 inch QF Mark XI[Note 1] was a 50-calibre, 4.7-inch (120 mm) naval gun mounted on Royal Navy (RN) and Allied destroyers during World War II.

It featured a 62 lb (28.1 kg) shell fired at 2,538 ft/second (774 m/s) to a maximum range of 21,240 yards (19,420 m) at 45 degrees of elevation.

The shells and cartridges were transferred from the hoists to the tilting tray of the fuze-setting machine by hand.

In the Battle of Pantelleria on 15 June 1942, HMS Marne, Matchless, and Ithuriel engaged a superior Italian task force.

The new 120/50 mm shell was heavy and powerful and the Italian destroyer was soon lying dead in the water, with a furious fire amidships.