Carnival president Christine Duffy and Carnival senior vice-president of new builds Ben Clement joined Tim Meyer, chief executive of Meyer Turku, to welcome the new vessel.
The addition comes after the line prepares to embark on its "largest-ever" period of growth in its 50-year history.
"We have so many reasons to celebrate now that Carnival Celebration has joined as the 24th ship in our fleet," said Duffy. "Now, more guests will experience all that our innovative Excel-class has brought to cruising.
"She represents the culmination of our 50th birthday while also shining a light on our bright future with so much more excitement to come."
