The 67-year-old was a guest at a wedding at Rottal Steading in Glen Clova at the weekend.
Police confirmed the death, saying the woman became unwell at around 9pm on Saturday.
Emergency services attended but she died soon after they arrived.
The woman has not been named by police.
Emergency response
A spokesman for Police Scotland said: “We received report of a 67-year-old woman having taken unwell at a premises in the Rottal area around 9pm on Saturday August 28 2021.
“Emergency services attended and the woman died a short time later.
“A report will be submitted to the Procurator Fiscal.”
Rottal Steading is a popular wedding venue in the heart of Glen Clova.
Its secluded location outside the Cairngorms National Park is 12 miles from the nearest town, Kirriemuir.