The TV star - who is known as 'The Beast' on the quiz show - has been shedding the pounds for a while and so far has lost 10 stone.
And he looked trimmer than ever as he attended the show's press evening at the Dominion Theatre in London.
Pictures showed Labbett in a white shirt and black jacket and trousers as he posed alongside dancer Kira Malou and presenter Hayley Palmer.
He tweeted after the show: "I had an absolute blast at Dirty Dancing at the Dominion tonight.
"Feel both joyfully energised and utterly past it at same time :)."
The quiz champion, 45, has previously revealed that he weighed 29 stone at his heaviest and that he was diagnosed with diabetes a few years ago.
I had an absolute blast at Dirty Dancing at the Dominion tonight. Feel both joyfully energised and utterly past it at same time :)
— Mark Labbett (@MarkLabbett) January 25, 2023
In 2021 he told The Sun that he was the lightest he had been in 25 years after dropping 10 stone.
“I’m now down to a 44-inch waist, my chest is 54 inches, while my neck measurements are down to 19 inches, which is fantastic for me and the top end of a normal man’s range," he said.
“My knees really feel the difference. I will never be athletic again but I just move so much better for not carrying that extra weight.”
Watch: Gloria Hunniford criticised for Mark Labbett 'belly' comment