The King was described as being in “good spirits“ by double world heptathlon champion Katarina Johnson-Thompson as he presented her with an MBE.
Charles returned to official public duties after cancelling a string of engagements at the end of last week, when he experienced temporary side effects from cancer treatment on Thursday.
The athlete was recognised for an outstanding track and field career during the Windsor Castle ceremony hosted by Charles.
Popular gardener and broadcaster Alan Titchmarsh also praised the King for his “boundless energy” despite his cancer diagnosis, as he was made a CBE.
The King welcomed dozens of recipients to Windsor Castle after spending a restful weekend and working on state business on Monday.
Ms Johnson-Thompson said after the ceremony: “He seemed in good spirits. You know it’s long, all day, because so many people are getting honoured today.
“So he seems in really good spirits and I’m happy to see that he’s fit and well.”
