Matt Smith 2010 to 2013

Although Steven Moffat expected to pick a middle-aged actor for the new Doctor,[13] Smith was aged 26 when cast. This made him the youngest actor to portray the Doctor, three years younger than Peter Davison was at the time he began his role as the Fifth Doctor.

The Doctor is a title character and the protagonist of the long-running BBC television science fiction series Doctor Who, and has also featured in two cinema feature films and one made-for-television movie, as well as a vast range of spin-off novels, audio dramas and comic strips connected to the series.
To date, eleven actors have played the role in the television series, with continuity being maintained by the ability of the character's species to regenerate. Several other actors have played the character on stage and film, in audio dramas, and in occasional special episodes of the series. The character's enduring popularity led the Daily Telegraph to dub him "Britain's favourite alien".