The news was announced on the official Doctor Who Twitter account on Friday morning.
Smith said: "To carry the Torch is an honour, one I thought I'd never get. I'm very excited!"
Who fans will remember David Tennant's Doctor famously carrying the London 2012 Olympic Torch in 2006 episode 'Fear Her'.
Smith has recently been filming the seventh series of the long-running sci-fi show, which will see the "heartbreaking" departures of companions Amy Pond (Karen Gillan) and Rory Williams (Arthur Darvill).
Smith has called the new episodes "extremely extraordinary", and said that he is "really, really pleased" with the Ponds' exit scripts.
