Charles, 71, is displaying “mild symptoms” but is in good health as he self isolates at home in Scotland, a spokesman said.
The Duchess of Cornwall, 72, has also been tested but does not have the virus.
In a statement, Clarence House said: “The Prince of Wales has tested positive for Coronavirus.
“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.
“In accordance with Government and medical advice, the Prince and the Duchess are now self-isolating at home in Scotland. The tests were carried out by the NHS in Aberdeenshire where they met the criteria required for testing.
“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.”