The latest contract follows the initial signing of a memorandum of agreement between the companies in July.
Deliveries of the two cruise ships are scheduled to take place in late 2023 and 2025, respectively.
Each vessel is based on next-generation platform design and will be capable of accommodating about 4,300 guests at lower berth.
Vessels will be dual-fuel powered primarily by the environmentally friendly advanced fuel technology liquefied natural gas (LNG), which will reduce air emissions and marine gas oil usage.
Each vessel will be designed to include the line’s MedallionClass platform and will be powered by their wearable device OceanMedallion technology.
Princess Cruises president Jan Swartz said: “Princess Cruises continues to grow globally, adding new ships to our fleet built by our long-time trusted shipbuilding partner, Fincantieri, who brings decades of expertise to these next-generation cruise ships.
“Even more exciting is that these two ships are being designed to include our MedallionClass platform, powered by OceanMedallion, the most advanced wearable device available within the global hospitality industry.”
The technology, which delivers personalised service and interactive entertainment, is currently available on Caribbean Princess and Regal Princess.
By the end of the year, MedallionClass platform will be activated on Royal Princess, Crown Princess, and Sky Princess ships.