Rumours that Coughlan would be starring in the sci-fi series had been doing the rounds after she was spotted around South Wales doing what appeared to be filming for Doctor Who's festive special.
During a press conference this week, Davies gave credence to the whispers.
"[We've got] Nicola Coughlan at Christmas. Not this Christmas, next Christmas. We're shooting Christmas 2024 now," he explained.
While he didn't share details on her Who character, we do know that Coughlan will appear as Queen Victoria in another festive special - the CBBC show Dodger, which also stars the Ninth Doctor, Christopher Eccleston. Doctor Who will return to BBC One and BBC iPlayer on November 25.
David Tennant will star as the 14th Doctor alongside comedian Catherine Tate who plays the Time Lord’s former companion Donna Noble.
The pair will star in three special episodes that will run each Saturday from November 25 to mark the show’s 60th anniversary.
The first episode set to air is called The Star Beast and will be followed by Wild Blue Yonder, airing on December 2 and The Giggle, which will air on December 9.
Sex Education and Barbie star Ncuti Gatwa will take over in the role of the Doctor over the festive period.
The actor will star alongside Coronation Street actress Millie Gibson, 19, who is playing the Doctor’s companion Ruby Sunday.