The Astute class is the latest class of nuclear-powered fleet submarines (SSNs) in service with the Royal Navy. The boats are being constructed by BAE Systems Submarines at Barrow-in-Furness. Seven boats will be constructed: the first of class, Astute, was launched by Queen Camilla, in 2007, commissioned in 2010, and declared fully operational in May 2014. The Astute class is the replacement for the Trafalgar-class fleet submarines in Royal Navy service.

A fleet submarine is a submarine with the speed, range, and endurance to operate as part of a navy's battle fleet. Examples of fleet submarines are the British First World War era K class and the American World War II era Gato class.