The actor told Evans: “I’ve actually been offered a part in Doctor Who, which I’m very excited about.”
Walliams continued: “I’ve said yes. I don’t think I can reveal much, I’ll just say I’m playing an alien.”
He added that he will be filming the role “in a few weeks”, meaning that his episode will feature in the second half of Series 6, airing in the Autumn.
The actor previously appeared alongside a Dalek in an episode of BBC One comedy series Come Fly With Me.