The Swiftsure class were a class of nuclear-powered fleet submarines in service with the Royal Navy from the early 1970s until 2010.
Six boats were built and commissioned. Swiftsure was decommissioned in 1992 due to damage suffered to her pressure hull during trials. Splendid followed in 2004 after defence cuts caused a reduction in the size of the RN submarine fleet. Spartan was decommissioned in January 2006, with Sovereign following on 12 September 2006. Superb was decommissioned on 26 September 2008. The remaining boat in the class, Sceptre, was decommissioned in December 2010. They are being replaced by the Astute-class submarines.
A few were upgraded with the capability to launch Tomahawk cruise missiles in addition to their original armaments of torpedoes, mines and anti-ship missiles. They were also the first class of Royal Navy submarines to be built with pump-jet shrouded pump-jet propulsors.