Answer: Stephen Hawking
All manner of famous people have appeared in the various incarnations of Star Trek over the years: Abraham Lincoln, Mark Twain, Genghis Khan, and Albert Einstein to name a few. Of all the famous people from our time and before that have appeared on Star Trek, however, there is only one person who has had the pleasure of playing their real-life identity: Stephen Hawking.
Hawking made an appearance as a holographic representation of himself in the sixth season of Star Trek: The Next Generation. In episode twenty-six, “Descent”, he appears in the Holodeck, along with actors portraying Isaac Newton and Albert Einstein, engaged in a round of poker with the ship’s resident android, Data.
The crew and actors recall Hawking’s visit fondly. While on a tour of the set, Hawking was shown the engine room with the ship’s warp core; he paused to key something into his voice-synthesizer and quipped, “I’m working on that.”
Image courtesy of Paramount.