The Doctor is the main character of Doctor Who. All incarnations of the Doctor that existed at the time of LEGO Dimensions' release appear and are playable in-game. They are:
- First Doctor, the original incarnation, who was played by William Hartnell from 1963 to 1966.
- Second Doctor, the second incarnation, played by Patrick Troughton from 1966 to 1969.
- Third Doctor, the third incarnation, played by Jon Pertwee from 1970 to 1974.
- Fourth Doctor, the fourth incarnation, played by Tom Baker from 1974 to 1981.
- Fifth Doctor, the fifth incarnation, played by Peter Davison from 1981 to 1984.
- Sixth Doctor, the sixth incarnation, played by Colin Baker from 1984 to 1986.
- Seventh Doctor, the seventh incarnation, played by Sylvester McCoy from 1986 to 1989.
- Eighth Doctor, the eighth incarnation, played by Paul McGann in 1996 and later 2013.
- War Doctor, the special war and ninth incarnation, played by John Hurt in 2013.
- Ninth Doctor, the tenth incarnation, played by Christopher Eccleston in 2005.
- Tenth Doctor, the eleventh incarnation, played by David Tennant from 2005 to 2010.
- Eleventh Doctor, the twelfth incarnation, played by Matt Smith from 2010 to 2013.
- Twelfth Doctor, the thirteenth incarnation, played by Peter Capaldi from 2013 to 2017.