The 7,800 tonne boat, which will be equipped with the latest cruise missiles, is the fourth of the Astute class, the largest and most powerful attack submarines ever built in Britain for the Royal Navy. Assembly of the submarine is expected to start later this year.
Lord Drayson, Minister for Defence Equipment and Support said:
"Audacious will join the three other submarines of the Astute class already under construction at the BAE Systems shipyard at Barrow-in-Furness in Cumbria.
"Today's announcement demonstrates our commitment to the attack submarine programme, as set out in the Defence Industrial Strategy. It also demonstrates our commitment to the Royal Navy, which needs these submarines to fulfil its duties around the globe. It demonstrates the best of British technology and our determination to develop and transform the UK Submarine industry over the coming years."
The First Sea Lord Admiral Sir Jonathon Band said:
"We need a versatile maritime force across the operational spectrum. Astute forms a key part of this future programme and is designed as a multi role platform. The first of these immensely powerful submarines, HMS Astute, is launched next month and I look forward to her entry into service with her sisters, Ambush and Artful - and now the fourth of the class, Audacious. These boats will help protect Britain's interests overseas for decades to come."