Sea Slug was a Royal Navy surface-to-air missile system built by Hawker Siddeley which came into service in the 1950's and was still in use at the time of the Falklands War, where its limited surface-to-surface attack capability was used to good effect. It was fitted to the County Class Destroyers which were specifically built to carry this weapons system. The magazine took up over two thirds of the ships length. The missile had four boosters which came away after launch it was powered by a cordite motor and was a beam riding missile. All the missile handling system onboard was hydraulic and this made it very manpower intensive and demanding to maintain. It has now passed out of commission by the Royal Navy.

This design is similar to the Bristol Bloodhound_SAM which was deployed in Germany during the Cold War.