Princess Cruises said it has reached an agreement to build a third in the class of ships that began with Royal Princess.
The new ship, to be built by Fincantieri, will carry 3,560 passengers at double occupancy and is scheduled for delivery in 2017.
Princess said the price is around 600 million euros, or just over $800 million at current exchange rates.
The Royal Princess was the largest ship to date for Princess when it was delivered in 2013. It was followed by the Regal Princess earlier this year.
Princess said the new ship will include its signature elements such as a soaring central atrium hub with multiple dining, entertainment and retail venues; the adults-only Sanctuary; the Movies Under the Stars cinema experience; and 80% of all cabins with balconies. The ship will also include some new innovations, Princess said.