The Time Lords are a fictional ancient race of extraterrestrial people in the British science fiction television series Doctor Who, of which the series' main protagonist, the Doctor, is a member. Time Lords are so named for their command of time travel technology and their non-linear perception of time. Originally, they were described as a powerful and wise race from the planet Gallifrey, from which the Doctor was a renegade; details beyond this were very limited for the first decade of the series. They later became integral to many episodes and stories as their role in the universe developed. For the first eight years after the series resumed in 2005, the Time Lords were said to have been destroyed during the Last Great Time War at some point in the show's continuity between the television movie in 1996 and the show's revival. In 2013, the 50th anniversary special "The Day of the Doctor" concerned this supposed destruction and their eventual survival.

"The Day of the Doctor" is a special episode of the British science fiction television programme Doctor Who, marking its 50th anniversary. It was written by Steven Moffat, who served as an executive producer alongside Faith Penhale. It was shown on BBC One on 23 November 2013, in both 2D and 3D. The special was broadcast simultaneously in 94 countries, and was shown concurrently in 3D in some cinemas. It achieved the Guinness World Record for the largest ever simulcast of a TV drama and won the Radio Times Audience Award at the 2014 British Academy Television Awards.