The 77-year-old, who recently returned from a hectic official overseas trip to Australia and Samoa, is reportedly resting at home.
On Tuesday afternoon, a Palace spokesperson stated: “Her Majesty The Queen is currently unwell with a chest infection, for which her doctors have advised a short period of rest.”
“With deep regret, Her Majesty has had to cancel her engagements for this week but she hopes to recover in time to attend this weekend’s Remembrance events as usual.
“She apologises to all those who may be inconvenienced or disappointed as a result.”
In the Queen’s place, the Duchess of Gloucester will attend the annual opening of the Field of Remembrance at Westminster Abbey on Thursday.
Queen Camilla has also withdrawn from a reception at Buckingham Palace for Olympic and Paralympic athletes, which was hosted by the King on the same evening.
It is reported that the Queen is currently resting at home. No additional information about her illness or treatment has been provided, but she is said to be under the care of doctors.
Prime Minister Sir Keir Starmer shared a message wishing the Queen well on social media. Sir Keir wrote: “On behalf of the whole country, I wish Her Majesty The Queen a speedy recovery.”
The chest infection comes shortly after the King and Queen had a spa break in India on their way back to the UK from their ten-day tour of Australia and Samoa.
A representative from Buckingham Palace confirmed that Their Majesties made a brief, private stopover in India to break up the long journey from Samoa.
Following their tour, a palace official stated that the King “genuinely loved” the trip and “genuinely thrived” on the Australian and Samoan schedule, noting that the experience improved “his spirits, his mood and his recovery.”
“In that sense, the tour, despite its demands, has been the perfect tonic.” He also mentioned that the monarch drew considerable strength from having the Queen with him, especially because she “keeps it real.”
Charles temporarily paused his cancer treatment during the long trip, but it has been confirmed that additional overseas visits are planned for next year as he continues to manage the disease.