Pop star Jimmy Osmond is being treated for a stroke that was diagnosed after he came off stage following a pantomime performance on Thursday.
Osmond, 55, was playing Captain Hook in Peter Pan at the Birmingham Hippodrome.
His spokesperson said the star went to hospital after "pushing through" the evening's performance. There are no further details about his condition.
He is part of the famous Osmond family and had chart hits including 1972's Long Haired Lover From Liverpool.
His spokesperson said: "On the evening of Thursday 27 December, after pushing through the evening's performance of Peter Pan at Birmingham Hippodrome, Jimmy Osmond was driven straight to hospital and diagnosed with a stroke.
"He is grateful for all the well wishes and will be taking time out in the new year."
Known as "Little" Jimmy, he is the youngest member of the Osmond family and became the youngest person to have a UK number one single when Long Haired Lover From Liverpool hit the top spot.
He was just nine at the time. In Japan, he also became a pop sensation and was known as "Jimmy Boy".
He went on to have further UK hits with Tweedle Dee and I'm Gonna Knock On Your Door, as well as recording and performing with his older siblings.
He has also starred in a string of stage musicals and pantos, and appeared on reality TV shows like I'm a Celebrity... Get Me Out of Here! in 2005 and Celebrity Masterchef in 2016.
Birmingham Hippodrome's chief executive Fiona Allan said: "Everyone here at Birmingham Hippodrome has been deeply saddened to hear of Jimmy's sudden illness.
"Jimmy loved being a part of the Hippodrome's well-renowned panto, and his portrayal of Captain Hook was both dastardly and heartwarming.
"He won the adoration not just of our audiences, but also of all our staff - we all send Jimmy and his family very best wishes for a speedy recovery."
Darren Day will replace him as Captain Hook in the pantomime.