The Duchess of Cambridge Kate Middleton, herself a royal princess, will name the Royal Princess cruise ship upon its debut in June, Princess Cruises said.
Her selection will give an extra boost to the publicity that Princess Cruises would otherwise receive in introducing the new ship, particularly in the U.K.
The ship will be formally named in a ceremony in Southampton, England, on June 13.
Middleton, 31, became a royal by marrying Prince William in 2011. She and William are expecting their first child in July.
Her selection follows the choice of William's mother, Princess Diana, in 1984 to christen the previous Princess ship to bear the Royal Princess name.
After several preview cruises, the 3,600 passenger Royal Princess will cruise in the Mediterranean this summer before heading to Fort Lauderdale in November for a winter season in the Caribbean.Follow Tom Stieghorst on Twitter @tstravelweekly.