The delivery ceremony was attended by Torstein Hagen, founder and chairman of Viking Cruises, while Fincantieri officials included ceo Giuseppe Bono, among others.
It has been an eventful week for Hagen and Viking, with 12 river vessels inaugurated in Amsterdam and Rostock on Tuesday.
The 47,800gt Viking Star can accommodate 930 passengers. The interiors were created by London-based SMC Design and Los Angeles-based Rottet Studios.
Viking Star will now embark on a shakedown cruise before its first revenue sailings. The ship is due to be named on May 17, Norwegian Constitution Day, in Bergen.
Next up for Viking Cruises' ocean fleet are Viking Sea and Viking Sky, both scheduled for delivery in 2016. The company has an option for a fourth ship.
Fincantieri has built 69 cruise ships since 1990 and other 15 passenger vessels currently are being designed or built in the group's yards.