Who Has Played the Same Character in All of the Star Trek Shows?
The character who has appeared in all of the Star Trek television series is William Riker, played by Jonathan Frakes. Riker first appeared in Encounter at Farpoint, the first episode of Star Trek: The Next Generation (TNG). This makes Riker one of the most prominent examples of an actor remaining consistent across a significant portion of the Star Trek franchise.
Another notable character is Leonard McCoy. Originally played by DeForest Kelley in the original series, his role was later reprised by Karl Urban in the reboot films. However, McCoy did not appear in every Star Trek series. If the question is interpreted to mean an actor portraying the same character across all series, then Riker fittingly stands alone in this regard.
Historical Context and Exceptions
DeForest Kelley had a brief cameo in the first episode of TNG titled "Encounter at Farpoint" as Admiral Leonard H. McCoy, marking the closest to continuous performance in multiple series. Leonard Nimoy also reprised his role as Spock in the two-part episode "Unification" of TNG before any of the other later series had premiered. Mark Lenard was also notable, appearing as Sarek in TOS and reappearing as Sarek in TNG, as well as playing several other roles across the franchise, making him a significant actor in Star Trek history.
Majel Barrett and Mark Lenard: Notable Exceptions
Majel Barrett came close to being the actress who played the same character across all series. She portrayed "Number One" in the original pilot of TOS and then served as the computer in every series in the franchise up to Voyager. Mark Lenard, on the other hand, played Sarek twice in TOS, and then reprised the character in TNG. Additionally, Lenard played different roles for the Star Trek franchise, which includes acting as the first known Romulan in the animated series, the first known Vulcan in "Amok Time," and culminating in being the first Star Trek actor to play all three major alien races in the franchise.
The Legacy of Mark Lenard
Mark Lenard's career in Star Trek is notable for the significant roles he played, such as the first known Romulan commander, the first known Vulcan apart from Spock, and the first Klingon with modern makeup and dialogue in "The Motion Picture". His performances set a historical precedent and influenced the franchise's direction. Lenard's character arcs span the entire Star Trek timeline, providing a unique perspective on the evolution of the show's alien races.
While no actor has appeared in every Star Trek series, Mark Lenard's contributions stand out for his continuity and impact on the franchise. He has truly embodied the spirit of Star Trek across multiple generations and series, making him a standout figure in the annals of Star Trek's history.