Clarence House has confirmed the duchess, 74, has tested positive for coronavirus.
Charles, 73, caught the virus last week and had to cancel a visit in Winchester.
Camilla tests positive for Covid
A Clarence House spokesman said on Monday: “Her Royal Highness The Duchess of Cornwall has tested positive for COVID-19 and is self-isolating.
“We continue to follow government guidelines.”
The duchess has had three vaccinations.
It comes after the Prince of Wales was forced into isolation after testing positive.
A statement from Clarence House last week read: “This morning The Prince of Wales has tested positive for COVID-19 and is now self-isolating.
“HRH is deeply disappointed not to be able to attend today’s events in Winchester and will look to reschedule his visit as soon as possible.”
Charles was due to unveil a statue of Licoricia of Winchester on Thursday.
The night before, Charles and Camilla had attended a reception to celebrate the British Asian Trust at London’s British Museum.
However, following Charles’ Covid diagnosis, royal fans expressed their fears for the Queen.
Reports claimed Charles had visited his mother, 95, before testing positive.
A Buckingham Palace source said Her Majesty wasn’t displaying symptoms.
Fears for the Queen
One fan said on Twitter: “I hope that our beautiful Queen is Covid free, and well in her very special year.”
Another wrote: “Oh, gosh no. I hope the Queen doesn’t have Covid. I love her.”
A third added: “I sincerely hope that the Queen does not have COVID.”
Meanwhile, Piers Morgan also expressed his own concerns.
He wrote on Twitter last week: “Prince Charles testing positive for Covid just 2 days after seeing the Queen is filling me with deep unease.”
What do you think of this story? Head to our Facebook page EntertainmentDailyFix and tell us.