Johnny Galecki Simon Helberg, Kunal Nayyar, Jim Parsons, Kaley Cuoco pose with Stan Lee, who guest stars as himself in an episode of The Big Bang Theory

5 ‘The Big Bang Theory’ Guest Stars That Shook up Long-Time Fans

‘The Big Bang Theory’ had dozens of cameos and roles from guest stars, but these are the five most memorable appearances

by Ross Tanenbaum

Published on February 22, 2023

3 min read

The Big Bang Theory had dozens of fantastic cameos and guest appearances from legendary celebrities. Audiences were surprised to see many of the world’s brightest scientists, hilarious comedians, and actors from some of the geekiest franchises, such as Star Wars, Star Trek, and Marvel. These guests gave the series some of its most memorable and funniest moments.

Here are 5 ‘The Big Bang Theory’ guests that shocked fans

Stan Lee

Stan Lee made a cameo in every Marvel film until his death in 2018, so it only makes sense for him to make a cameo in The Big Bang Theory. In “The Excelsior Acquisition” from Season 3, Sheldon misses an opportunity to meet Lee at a local comic book store. Fortunately, Penny is able to get his address, and the two go to his house, hoping he’ll sign something for Sheldon.

Lee isn’t pleased that random fans show up at his house and calls the police on them, leading to Sheldon getting a restraining order from him. While most people wouldn’t want to be banned from seeing their idols, Sheldon most likely claims it as a badge of honor.

Stephen Hawking

Stephen Hawking was a renowned physicist and idol to Leonard and Sheldon. He first appeared in “The Hawking Excitation” from Season 5. In the episode, Howard has the opportunity to work with Hawking, and Sheldon begs Howard to give him his paper on the Higgs boson particle. After taking advantage of Sheldon’s desperation, he does give his paper to Hawking, leading to a meeting between Sheldon and the English physicist.

While many fans recognize Hawking’s voice, many were surprised to see him appear at the end of the episode. Hawking shows that even in his condition, he still had a sense of humor, which he uses to poke fun at Sheldon.

Leonard Nimoy

Leonard Nimoy is another hero of Sheldon’s, mainly for his portrayal of Spock in the original Star Trek series. In “The Transporter Malfunction” from Season 5, Sheldon and Leonard receive vintage Star Trek transporter toys. However, they object to playing with them as opening them diminishes their values. Nimoy appears as the voice of a Spock action figure who convinces Sheldon to use a transporter.

When it breaks, Sheldon replaces his with Leonard’s but becomes racked with guilt over it. The figure then begins to shun Sheldon and convinces him to do the right thing. While Nimoy doesn’t appear physically here, it’s still great to hear his voice and the hilarious delivery he gives to the action figure.

Mark Hamill

He didn’t appear as a guest on The Big Bang Theory until season 11, but Mark Hamill was due to pop up at some point. In “The Bow Tie Asymmetry,” Hamill agrees to officiate Sheldon and Amy’s wedding after Howard finds his lost dog. However, Sheldon and Amy are running late, leading to Hamill being ambushed with Star Wars questions by the guests. Fortunately, all goes well, as Sheldon is delighted to see Luke Skywalker officiating his wedding.

James Earl Jones

James Earl Jones is an esteemed actor, best known for his voice roles as Mufasa in The Lion King and as Darth Vader in Star Wars. Sheldon is overwhelmed when he meets him at a restaurant, and Jones is more than happy to spend time with his fans. The pair have a wild night, including karaoke, a Ferris wheel ride, and playing ding-dong-ditch at Carrie Fisher’s house.

While Jones is in his 80s in his episode, he behaves like someone in his 20s. It’s phenomenal to see Jones play along with this hilarious script that turns this menacing persona into a lovable goof.