Prince Carl Philip, third in line to the throne of Sweden, will marry his longtime girlfriend, 29-year-old former model Sofia Hellqvist, the royal court said on Friday.
"The wedding date has not yet been decided but it is planned to take place during the summer of 2015," it announced in a statement.
Sweden is a constitutional monarchy and the king has no political power. Public support for the royal family has weakened slightly in recent years, but remains fairly broad in otherwise egalitarian Sweden.
Carl Philip's father, Carl XVI Gustaf, has been King of Sweden since 1973. His first daughter, Victoria, became the heir apparent in 1980 by a constitutional reform that meant the throne would be inherited by the monarch's eldest child without regard to gender.
Carl Philip, 35, is third in line to the throne after his sister Victoria and her daughter Estelle.