The 35-year-old, who starred in the British award-winning drama "Broadchurch", will take over from Scottish actor Peter Capaldi later this year as 13th incarnation of the Time Lord.
Fans were treated to a brief glimpse of Whittaker, walking towards the Tardis in a forest, in a clip shown after the Wimbledon tennis final on BBC television.
But she will not take up the role, which Capaldi has held since 2013, until he leaves the show by "regenerating" into the new doctor during the Christmas special.
The adventures of the doctor -- a time travelling, humanoid alien who traverses the universe -- have maintained a loyal following since they were first aired in 1963.
The show is aired around the world, and marked its 50th anniversary four years ago with a special episode screened simultaneously in nearly 100 countries.
The choice of a woman as the new doctor was well trailed but is likely to be highly controversial, with some fans taking to Twitter to accused the producers of ruining the show.