The Type 42 destroyer is a class of destroyer serving with the Royal Navy of the United Kingdom. The class is also known as the Sheffield class after the first ship in the class.

The class was designed in the late 1960s to provide fleet area air-defence. In total fourteen vessels were constructed in three batches, eight of which remain in service.

The ships of this class are armed with the ageing Sea Dart medium-range air defence missile system, which also has a limited anti-ship capability. In addition they have a useful gun armament.

They have been useful work horses of the fleet for many years and are equipped with the latest communication and sensor equipment.

They also carry the high-speed multi-purpose Lynx helicopter armed with anti-submarine weapons and the Sea Skua anti-ship missile which is controlled by the Sea Spray search radar.

In addition to their air defence role, the Type 42 Class vessels have an extensive general purpose capability as patrol vessels, capable of a wide range of maritime enforcement and humanitarian assistance operations.