The new star of Doctor Who will be revealed in a special live programme on Sunday, the BBC has announced.
The half-hour show, presented by Zoe Ball, will feature an interview with the new lead, as well as 11th Doctor Matt Smith and executive producer Steven Moffat.
"The decision is made and the time has come to reveal who's taking over the Tardis," Moffat said.
"For the last of the Time Lords, the clock is striking twelve."
Doctor Who Live: The Next Doctor, is on BBC One at 7pm on 4 August.
According to the official announcement, Ball "will unveil the 12th Doctor in the first ever interview in front of a live studio audience set against the backdrop of a swirling vortex, amongst Daleks and the Tardis".
Smith, who has played the Time Lord since 2010, announced in June that he would be bowing out in this year's Christmas special.
The announcement sparked much speculation about who might take over, with Peter Capaldi, Ben Daniels, Rory Kinnear and Ben Whishaw among the bookies' favourites.