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The de Havilland Sea Venom was a British postwar carrier-capable jet aircraft developed from the de Havilland Venom. It served with the Royal Navy Fleet Air Arm and with the Royal Australian Navy. The French Navy operated the Aquilon, a version of the Sea Venom FAW.20 licence-built by SNCASE (Sud-Est).
The Sea Venom was the navalised version of the Venom NF.2 two-seat night fighter, and was used as an all-weather interceptor by the FAA. The necessary modifications for use on the Royal Navy's aircraft carriers included folding wings, a tailhook (which retracted into a characteristic "lip" over the jetpipe) and strengthened, long-stroke undercarriage. The canopy was modified to allow ejection from underwater. The first prototype made its first flight in 1951, and began carrier trials that same year. A further two prototypes were built. The first production Sea Venom took the designation FAW.20 (Fighter, All-Weather). It was powered by a single de Havilland Ghost 103 turbojet engine and its armament was the same as the RAF version. The next variant was the FAW.21, which included the modifications introduced in the Venom NF.2A and NF.3. Some of these modifications included the Ghost 104 engine, a clear-view canopy and American radar. The final Royal Navy variant was the FAW.22 powered by the Ghost 105 engine. 39 of this type were built in 1957–58. Some were later fitted out with the de Havilland Firestreak air-to-air missile.
Seven FAW.21s were modified in 1958 for Electronic countermeasures (ECM) purposes, with the cannon replaced by the ECM equipment. These became the ECM.21. 831 Naval Air Squadron, the sole squadron to be equipped with it, was shore-based at RAF Watton from 1963 and disbanded in 1966. Converted FAW.22s were similarly known as the ECM.22.A modernised Sea Venom project, the DH.116 with swept wings and upgraded radar was considered, but cancelled as the Royal Navy believed that any replacement needed two engines. The de Havilland Sea Vixen ultimately replaced the Sea Venom.