The Hawker Siddeley Nimrod was built as a replacement for the Avro Shackleton maritime patrol aircraft. Based on the de Havilland Comet (the world's first operational jet airliner), it was also the first jet patrol aircraft in service by any country. Externally it has some notable differences from the Comet, mainly a shortened fuselage, a weapons bay, a deepened nose with search radar, and a prominent Magnetic Anomaly Detector (MAD) boom in the rear.The Nimrod is also equipped with ESM sensors and the ability to carry a wide array of weaponry such as torpedoes, anti-ship missiles and even air-to-air missiles in addition to sonobuoys and other stores. RAF Nimrods first saw action during the Falklands War where they were hastily equipped with inflight-refuelling probes although their main duties were over the Atlantic as well as the Mediterranean, Baltic and North Sea during the Cold War. Considered by some to be the finest patrol aircraft in the world, they are still in widespread use with the RAF today as revealed by their recent use in Afghanistan and Iraq.

Design of the Nimrod began as early as 1964 using conversions of the Comet 4C airliner with Spey engines. The first prototype flew on 23 May 1967 with service deliveries beginning in 1969. The initial batch of production aircraft were known as the Nimrod MR.1 which were later upgraded with vastly improved avionics as the MR.2, the main maritime patrol variant currently in service. A dedicated Elint platform is known as the Nimrod R.1 and differs from the patrol variants due to the installation of a number of receiver domes including one which replaces the MAD boom, these were frequently spotted near the frontiers of the Warsaw Pact performing intelligence gathering missions. Other versions include the controversial Nimrod AEW.3 airborne warning system which was eventually aborted in favor of the US E-3 and the Nimrod MRA.4 which is expected to replace the MR.2 in the next decade.