According to the Norwegian Royal Court, Queen Sonja is scheduled to attend the wedding along with Crown Prince Haakon and Crown Princess Mette-Marit, and Princess Märtha-Louise and her husband Ari Behn.
However, Harald himself will be absent.
“The King has another private engagement, and will not be at the wedding,” a court spokesperson told Dagbladet.
The spokesperson would not clarify whether Harald had been invited or not.
Last year, Sweden's King Carl XVI Gustav ruffled Norwegian feathers by at first declining to attend the bicentenary of the Norwegian constitution.
He later relented and attended the ceremony on May 17.
Kjell Arne Totland, a Royal expert with TV2 told Dagbladet that it was quite common for Norway's King and Queen to attend events alone.
“In April Harald went alone to Copenhagen for the 75th birthday of Queen Margrethe,” he said. “Both King and Queen were invited both to there and to Stockholm, but this time it is the king who has other plans for the weekend.”