In the official pictures, Haakon is accompanied by wife Princess Mette-Marit and their two children, Princess Ingrid Alexandra, ten, and Prince Sverre Magnus, 8.
Young Marius Borg Hoiby, Princess Mette-Marit's teenage son from a previous relationship, also appears in the pictures which were taken in Kristiansand, in Southern Norway.
The Norwegian royal family, who are dressed in matching neutral hues, can be seen perched on rocks overlooking the sea.
Last year, Prince Haakon celebrated his 40th birthday with a festival themed party. He kicked off the celebrations by arriving at Skaugum Palace by parachute.
Haakon's wife Princess Mette-Marit had organised the party to perfection, ensuring that the couple's blue-blooded friends, King Willem-Alexander and Queen Maxima of the Netherlands and Princess Mary of Denmark, were present.
Live music, including a performance from the birthday prince himself, was the event's highlight and when the royal took to the stage with his sister, Princess Märtha Louise, he thanked the host of artists and performers that made the occasion so special.