The Astute-class are the newest nuclear attack submarines developed for the Royal Navy. Displacing almost half again as much as their predecessors, the Trafalgar-class, they are the largest British attack subs ever built and incorporate a host of improvements (some of which have been introduced and tested recently in the Trafalgar boats). The Astute subs features significant automation which has resulted in a smaller complement. Most noteworthy is the replacement of the SCMS system with the ACOS (Astute Combat Management System), which integrates sensor input into real time images. Sonar is the advanced Type 2076 and is coupled with a DESA 25 echosounder; they are also the first UK subs to be equipped with an optronic mast rather than a periscope. With a top speed of 30 knots, the Astutes are slightly slower than their predecessors but have almost double the range thanks to their more modern Rolls-Royce PWR 2 nuclear reactors which in theory allow them to circumnavigate the world 40 times before refueling. A pump jet propulsion is fitted on a single shaft, and is driven by twin Alstom turbines. The Astute subs are armed with six 21-in torpedo tubes capable of carrying Spearfish torpedoes as well as Tomahawk Block IV land-attack missiles. Special forces can also be deployed via a dry deck shelter, making it the only class aside from the US Virginia-class to feature this capability by default. It is believed that the Astute subs are among the quietest in the world (anechoic tiles are fitted on the hull), and along with their excellent sonar make them formidable hunter-killers. Only two of seven planned boats are currently in service.

None of the two ships currently in service have been in action, although the lead ship, HMS Astute, became notorious for a deadly shooting incident involving a crew member in 2011.