The Welsh-born princess, who is 92 and is the widow of the king’s uncle, Prince Bertil, has been a regular fixture at the Nobel ceremonies. She attended last year’s prizegiving at the Stockholm Concert House, but missed the banquet at City Hall.
The Royal Court was able to confirm on Friday that King Carl Gustaf’s aunt would not attend this year.
“The Princess is an elderly lady,” said spokesman Juan Navas by way of explanation.
The Nobel festivities are the highlight of the royal calendar. Other senior members of the Royal Family are expected to attend.