London: Queen Elizabeth, 95, has tested positive for COVID and is experiencing mild symptoms but expects to continue light duties this week, Buckingham Palace said on Sunday.
"The queen has today tested positive for COVID," the Palace said.
The news comes after Prince Charles, the queen's eldest son and heir, tested positive on February 10, two days after meeting his mother at Windsor.
No information was given then on whether Queen Elizabeth - who this month marked 70 years on the throne - had taken any COVID-19 tests herself.
She resumed in-person audiences at the castle last week, but complained to one attendee of suffering from stiffness and was photographed holding a walking stick.
"Buckingham Palace confirm that the queen has today tested positive for COVID-19," a statement from the palace said.
"Her Majesty is experiencing mild cold-like symptoms but expects to continue light duties at Windsor over the coming week," it said.
"She will continue to receive medical attention and will follow all the appropriate guidelines."
While normally secretive about the queen's health, the palace has previously confirmed she is fully vaccinated against COVID-19.
Britain's Press Association said "it is understood a number of cases have also been diagnosed among the Windsor Castle team".
There was no immediate comment from Prime Minister Boris Johnson. But his health secretary, Sajid Javid, tweeted: "Wishing Her Majesty The Queen a quick recovery."
Keir Starmer, leader of the main opposition Labour party, also tweeted his best wishes for "a speedy recovery", adding: "Get well soon, Ma'am."
Nationwide celebrations to mark the queen's Platinum Jubilee are due to be held in June.
On the eve of the 70th anniversary of her accession on February 6, the monarch held a reception for locals at Sandringham, her estate in eastern England.
It was reportedly her largest in-person public engagement since an unexplained health issue saw her spend a night in hospital last October.
The COVID-19 scare comes with the royal family mired in scandals.
The queen's second son, Prince Andrew, settled a sexual assault civil lawsuit in the United States last week, reportedly for £12 million ($16.3 million) - which newspapers claim she will partly fund.
The queen, whose husband Prince Philip died aged 99 last April, has spent much of the coronavirus pandemic at Windsor Castle, with a reduced number of household staff dubbed "HMS Bubble".
Respecting the government's then rules on COVID-19 distancing, she sat alone at Philip's funeral.
