The 41-year-old is best known for Channel 4 comedy panel show The Last Leg, where he appears alongside Adam Hills and Alex Brooker, and has fronted his own semi-autobiographical BBC Three show, Josh, as well as hosting the Dave panel show Hypothetical.
It was announced on Strictly: It Takes Two on Monday that he will be paired with professional dancer Karen Hauer, who competed with former footballer Paul Merson on this year’s main series until he became the fourth celebrity to be eliminated.
Widdicombe said: “I am utterly terrified this will end in humiliation and worried I’m going to be so bad I will ruin Christmas for the nation.
“Why have I done this?”
He co-hosts the podcast Parenting Hell with comedian Rob Beckett, and has appeared on comedy panel shows including Smart TV, QI, A League Of Their Own, Mel Giedroyc: Unforgivable, and Have I Got News For You, as well as being a guest host on Pointless.
He will be joined by five other celebrities for the competition.
Widdicombe previously won the first series of Taskmaster, and the Champion of Champions special of the comedy show.
Regular Strictly judges Craig Revel Horwood, Motsi Mabuse, Anton Du Beke and Shirley Ballas will decide the winner of the Christmas special along with votes from the studio audience.
Last year, EastEnders actor Jamie Borthwick and professional dancer Nancy Xu lifted the Silver Star trophy.
Borthwick is currently competing in the main show with professional partner Michelle Tsiakkas, while Xu and her celebrity partner, The X Factor winner and singer Shayne Ward, left after losing the dance-off in Sunday’s results show.
The rest of the Christmas special line-up will be announced on Strictly: It Takes Two in due course, the BBC said.
