The Valeyard

The Valeyard (/ˈvæliɑː(r)d/, VALLEY-ard) is a fictional character from the long-running British science fiction television series Doctor Who. He appears in the show's twenty-third season, dubbed The Trial of a Time Lord. The season's four serials are interconnected through one overarching plot line in which the Valeyard serves as a court prosecutor in the trial of the Sixth Doctor. Within the series narrative, the Doctor is an alien who hails from a race known as the Time Lords. They travel in time and space in the TARDIS, frequently with companions. At the end of the Doctor's life, the Doctor regenerates, changing their physical appearance and aspects of their personality.

Toward the end of the trial, the Valeyard is revealed to secretly be an incarnation of the Doctor, being an "amalgamation of the darker sides" of the Doctor who hails from somewhere toward the end of the Doctor's life. The Valeyard had been working with the Time Lords to incriminate the Doctor in exchange for the Doctor's remaining regenerations. The Valeyard attempts to escape and destroy the Time Lords but is stopped by the Doctor. The Valeyard is presumed dead but is revealed to have escaped at the end of the episode. The Valeyard has subsequently appeared in various pieces of Doctor Who spin-off media.

The Valeyard was introduced by the show's then-producer John Nathan-Turner and the show's script editor Eric Saward, who created him to serve as the prosecutor of the trial and act as an overarching antagonist of the season in favor of character the Master, whom Saward felt would be too obvious as an antagonist. Though the Valeyard was originally supposed to have his fate left unknown, alongside the Doctor's, to create a shocking ending, rewrites would result in the Valeyard surviving, allowing him to return in later episodes. The Valeyard has been portrayed by Michael Jayston in all of his appearances, including in audio dramas released following The Trial of a Time Lord.

The Valeyard has been met with a positive response for his role in the narrative. He has been the subject of analysis due to his relationship with the Doctor and the nature of his existence within the series' narrative.