Prince Charles, the eldest son and heir to Queen Elizabeth II, is showing mild symptoms of the new coronavirus but "otherwise remains in good health", his office said on Wednesday.
The 71-year-old is self-isolating in Scotland along with his wife Camilla, who was also tested but does not have COVID-19, Clarence House said.
In a separate statement, Buckingham Palace said the queen, 93, was in "good health" and had not seen her son for two weeks.
"The Prince of Wales has tested positive for coronavirus," Charles' office said in a statement.
"He has been displaying mild symptoms but otherwise remains in good health and has been working from home throughout the last few days as usual. "The Duchess of Cornwall (Camilla) has also been tested but does not have the virus. "In accordance with government and medical advice, the prince and the duchess are now self-isolating at home in Scotland."
The couple were tested by the state-run National Health Service (NHS) in Aberdeenshire in northeast Scotland, it said.
"It is not possible to ascertain from whom the prince caught the virus owing to the high number of engagements he carried out in his public role during recent weeks," it added.