The Twelfth Doctor is the protagonist in Doctor Who in 2017.
Doctor Who (series 10) . Preceded by a Christmas special in December 2016 , `` The Return of Doctor Mysterio '' , the series is the third and final series starring Peter Capaldi as the Twelfth Doctor , an incarnation of the Doctor , an alien Time Lord who travels through time and space in his TARDIS , which appears to be a British police box on the outside ; Capaldi announced in January 2017 that he would be stepping down from the role after the tenth series . The Twelfth Doctor is an incarnation of the Doctor , the protagonist of the BBC science fiction television programme Doctor Who . On 30 January 2017 , Capaldi announced he would be leaving the programme , with the 2017 Christmas episode being his last .