Planer is best known for his role as TV hippy Neil in the classic comedy series but he has also appeared in many West End musicals, including Evita, Chicago, We Will Rock You, Wicked and Hairspray.
The live show, first announced in May, is touring nine UK cities this Autumn and will feature Daleks, Cybermen, Clockwork Droids, Silurians and Weeping Angels.
Planer will act as the production's lynchpin, starring as travelling showman Vorgensen who journeys the galaxy spreading tales of the Doctor's exploits and using his 'minimiser' gadget he can conjure up any of the Time Lord's foes for his audience.
Looking forward to the production Planer said
I'm incredibly excited to be joining Doctor Who Live and this role is something of a boyhood dream come true. My character Vorgenson, who has been developed specially for the show by Steven Moffat, is the Greatest Showman in the Galaxy and using his incredible invention, The Minimiser, he can make any Doctor Who character appear on stage as part of his travelling show dedicated to his hero.
Matt Smith will appear via filmed sequences which have been made just for the stage show and renowned illusionists The Twins have devised stunts which will enable a Dalek to be seen flying during the performances.
Actor Nick Briggs, who has voiced numerous monsters for the series including Daleks and Cybermen, will also be in the live cast, playing Winston Churchill in addition to some of the villains.
The tour begins at London's Wembley Arena on October 8 with further details at www.doctorwholive.com.