The Big Bang Theory has welcomed a long list of famous faces on to the show over its 12 years on air.
While some, including Billy Bob Thornton, Octavia Spencer and Regina King, played fictional characters, many appeared as themselves.
Below is a selection of some of the celebrities who guest starred.
Professor Stephen Hawking
The esteemed physicist made seven appearances on The Big Bang Theory, most notably in season five episode 21, The Hawking Excitation.
Hawking visits the university where the main characters work, causing Sheldon – who later faints in front of his idol – to demand Howard set up a meeting between the pair.
The second man on the Moon appeared in season six episode five, The Holographic Excitation.
Aldrin proved he was up for a laugh by gently mocking himself, being shown on screen reminding a group of children he had been to space.
Fisher, best known as Princess Leia in the Star Wars franchise, appeared in season seven episode The Convention Conundrum.
Her Star Wars co-star James Earl Jones brings Sheldon to her house before they ring the bell and run away, leaving Fisher on the doorstep holding a baseball bat.
Sheldon plays a crucial role in another celebrity appearance on The Big Bang Theory, this time one involving Marvel supremo and comic book pioneer Stan Lee.
Lee, who appeared in season three episode The Excelsior Acquisition, wore a Fantastic Four robe when opening the door to Sheldon and Penny, before becoming annoyed and calling the police.
West is best known for his portrayal of Batman in the 1960s series. He made a guest appearance on The Big Bang Theory’s 200th episode in 2016.
West was seen arguing with Leonard, Howard and Rajesh over who was the best Batman.
Shatner’s place in the sci-fi hall of fame is certain thanks to his portrayal of captain James T Kirk in the Star Trek franchise.
He made a cameo in Big Bang Theory’s 12th season, meeting a starstruck Sheldon who later throws up after meeting his hero.
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Last night, I went to Stage 25, now known as The Big Bang Theory Stage, and watched the taping of the final episode of the show that has brought more joy into my life than anything else I've ever done in my professional career. I have a lot of feelings and emotions to unpack, and they are all too raw and turbulent to do that today. Maybe after I go to the wrap party tonight. Maybe in a few days. Maybe it's too personal to ever properly convey what it means and has meant to me since I joined the show in the second season. Maybe I'll try right now and see what comes out. I think it's fair to say that if I built a tripod out of my career, the main legs would be Stand By Me, Star Trek, and The Big Bang Theory. It kind of blows me away that I get to say that. It is remarkable to me that I have gotten to have all of these things in my life, when honestly just ONE of them would be more than anyone could hope for on his or her resume. Mainstream Hollywood doesn't seem to be especially interested in me and what I bring to a production these days. I don't know why, and I don't know if I'll ever be able to do anything to change that, but I can confidently say that I probably have an on-camera acting career today because of Big Bang Theory, and anything I do on camera for the rest of my career will stand on the shoulders of the work I've had the privilege and honor to perform over the last decade. But all of that is just math and *work*, and while I'm grateful for the work, and proud of the work, what I will cherish for the rest of my life are the friends I've made among the cast, writers, and crew. This is a picture of me with Kevin Sussman, who was in my very first episode way back before I had any grey in my beard, and I love it, because it's this silly thing we did whenever we worked together on the stage. "Hey, let's take a super awkward selfie," I would say to Kevin, and then this would happen. It's moments like this, and relationships like this, that truly matter and make the difference in a life, and I'm so lucky and grateful that I have had so many moments like this, with these amazing humans.
Wheaton, who as a child star played Wesley Crusher on the television series Star Trek: The Next Generation, made frequent appearances on The Big Bang Theory.
Often portrayed as an enemy of Sheldon, Wheaton shared an emotional post on Instagram as the show was ending, praising The Big Bang Theory for including him while “mainstream Hollywood doesn’t seem to be especially interested in me and what I bring to a production these days”.
One of the richest men in the world and co-founder of Microsoft, Gates appeared on episode 18 of season 11, The Gates Excitation.
The billionaire bumps into Leonard, Howard and Rajesh in a hotel lobby.
- Press Association