Hugh Bonneville appeared on The One Show on Thursday night, to join hosts Alex Jones and Gethin Jones.
But viewers failed to realise it was even him when he first appeared, as the actor revealed his huge weight loss.
The Downton Abbey actor looked “unrecognisable” according to fans tuning in, as many had to double take.
Revealing his lockdown transformation on the show, he caused quite the reaction on Twitter as many noticed how different he looked.
Taking to Twitter, viewers shared their reactions unable to believe it was the same person – with him also unveiling a slightly different hairdo.
One fan said: “Wow, I didn’t recognise Hugh Bonneville on #TheOneShow to start with! What a transformation!”
Another tweeted: “Holy hell. Bonneville has not been scoffing the biscuits during lockdown.”
A third added: “Almost didn’t recognise Hugh Bonneville on #TheOneShow. Lost so much weight.”
Alex later read out comments on the show, claiming there was “a lot of love” for Hugh.
The actor laughed off one tweet from a fan who said he looked “amazing”.
Hug recently revealed all on his weight loss, with him hiring a personal trainer.
He was on the show to announce some special news to a guest.
Hugh has been working on a project to thank volunteers during lockdown, with the creation of pin badges to award someone who deserves a thank you.
Children had entered a competition to design the pins, with a finalist appearing on The One show.
It’s then he declared she had in fact won with her design.
The One Show airs weekdays at 7pm on BBC One.