Charles was cheered by patients and staff at York Hospital, as he toured the site ahead of the opening of the Sir Robert Ogden Macmillan Cancer Centre.
He met patients including Lou Rhodes, 49, who is living with stage 4 secondary breast cancer, and was involved in the design and development of the centre as a patient representative.
Here are the best pictures from the visit provided by James Glossop of The Times via The Press Association:
5. King Charles III, Patron of Macmillan Cancer Support, speaks with members of staff
As he left the hospital through the main reception, he was greeted with cheers from patients and staff waiting to see him, and stopped to talk to some. James Glossop/The Times/PA Wire Photo: James Glossop/The Times
6. King Charles III, Patron of Macmillan Cancer Support, speaks with staff in the new garden
King Charles III, Patron of Macmillan Cancer Support, speaks with staff in the new garden during a visit to the site of newly redeveloped Sir Robert Ogden Macmillan Cancer Centre in York Hospital. James Glossop/The Times/PA Wire Photo: James Glossop/The Times
7. King Charles III, Patron of Macmillan Cancer Support, waves to well-wishers
King Charles III, Patron of Macmillan Cancer Support, waves to well-wishers James Glossop/The Times/PA Wire Photo: James Glossop/The Times
8. King Charles III, Patron of Macmillan Cancer Support, arrives for a visit to the site
King Charles III, Patron of Macmillan Cancer Support, arrives for a visit to the site of newly redeveloped Sir Robert Ogden Macmillan Cancer Centre in York Hospital. James Glossop/The Times/PA Wire Photo: James Glossop/The Times