The Hawker Siddeley Nimrod was a maritime patrol aircraft developed and operated by the United Kingdom. It was an extensive modification of the de Havilland Comet, the world’s first operational jet airliner. It was originally designed by de Havilland’s successor firm, Hawker Siddeley; further development and maintenance work was undertaken by Hawker Siddeley’s own successor companies, British Aerospace and BAE Systems, respectively.

Designed in response to a requirement issued by the Royal Air Force (RAF) to replace its fleet of ageing Avro Shackletons, the Nimrod MR1/MR2s were primarily fixed-wing aerial platforms for anti-submarine warfare (ASW) operations; secondary roles included maritime surveillance and anti-surface warfare. It served from the early 1970s until March 2010. The intended replacement was to be extensively rebuilt Nimrod MR2s, designated Nimrod MRA4; however due to considerable delays, repeated cost overruns, and financial cutbacks, the development of the MRA4 was abandoned in 2010.

In addition to the three Maritime Reconnaissance variants, two further Nimrod types were developed. The RAF operated a small number of the Nimrod R1, an electronic intelligence gathering (ELINT) variant. A dedicated airborne early warning platform, the Nimrod AEW3 was in development from late 1970s to the mid-1980s; however, much like the MRA4, considerable problems were encountered in development and thus the project was cancelled in 1986 in favour of an off-the-shelf solution in the Boeing E-3 Sentry. All Nimrod variants had been retired by mid-2011.