Princess Cruises has signed final contracts for two new vessels at Fincantieri in Italy.
A preliminary deal for the 175,000-gt pair was agreed last July.
They will be the largest such ships ever built in Italy.
The Monfalcone yard will deliver them in late 2023 and in spring 2025.
The units will house 4,300 guests and will be the first Princess vessels to be dual-fuel, powered primarily by LNG.
"Princess Cruises continues to grow globally - adding new ships to our fleet built by our long-time trusted ship building partner, Fincantieri, who brings decades of expertise to these next-generation cruiseships," said Jan Swartz, Princess Cruises president.
Fincantieri CEO Giuseppe Bono added: "This result proves, once again, the trust we receive from the market, which allows us to look to the future with ambition.
"We firmly believe that a new class of Princess Cruises' ships, one of Carnival Group's top brands, can stem from this promising project.
"In fact, for Princess Cruises, we have received orders for 21 ships, another unprecedented result in this industry."
Princess has five ships being built over the next six years.
