SSN-AUKUS

	Rendering of SSN-AUKUS submarine (BAE Systems)
Class overview
Name	SSN-AUKUS, SSN-A
Builders	BAE Systems Submarines, Barrow-in-Furness (United Kingdom); ASC and BAE Systems, Osborne Naval Shipyard (Australia);
Operators	Royal Navy; Royal Australian Navy;
Preceded by	Astute class (RN); Collins class (RAN);
Built	From late 2020s to 2050s (United Kingdom); From late 2030s to 2040s (Australia);
In service	From late 2030s (United Kingdom); From early 2040s (Australia);
Planned	Up to 12 (United Kingdom); 5 (Australia);
General characteristics (conceptual)
Type	Nuclear attack submarine
Displacement	Over 10,000 tonnes (9,800 long tons)
Propulsion	PWR nuclear reactor
Sensors &; processing systems	Evolved AN/BYG-1 Combat Management System
Armament	Mk-48 torpedoes and missiles

The SSN-AUKUS, also known as the SSN-A, is a planned class of nuclear-powered attack submarine (SSN) intended to enter service with the United Kingdom's Royal Navy in the late 2030s and Royal Australian Navy in the early 2040s. The class will replace the UK's Astute-class and Australia's Collins-class submarines.

The UK commenced an Astute class replacement project in 2018, which was later named the Submersible Ship Nuclear Replacement (SSNR). The ongoing SSNR design was renamed SSN-AUKUS in March 2023, under the 2021 AUKUS trilateral security partnership, when Australia joined the programme and additional US technology was incorporated into the design.

The UK plans to build up to twelve SSN-AUKUS submarines. Australia plans to build five SSN-AUKUS submarines in addition to acquiring three nuclear-powered Virginia-class submarines from the United States.

When in service with the Royal Navy and the Royal Australian Navy, submarine crews will train and patrol together and undertake joint maintenance and support. Components and parts will be shared with the US.

The class will be powered by Rolls-Royce's pressurised water reactors (PWR). The submarines will displace over 10,000 tonnes.