The QF 4.5-inch Gun is a naval artillery piece developed in the early 20th century, primarily used by the Royal Navy. It was designed to provide effective fire support against surface ships and aircraft. The gun has a caliber of 4.5 inches (114 mm) and was typically mounted on various classes of warships, including destroyers and cruisers. This gun was notable for its versatility and relatively high rate of fire, making it suitable for both anti-surface and anti-aircraft roles. It saw extensive service during World War II and remained in use for several decades, contributing to naval operations in various conflicts.