The Cast Of The Big Bang Theory's Transformation Over The Years

The cast of The Big Bang Theory has maintained their ubiquitous status within the pop culture zeitgeist for well over a decade. Despite a slight drop in ratings later on in its 12-year run, this hit CBS series has boasted an audience of millions — a rarity in the age of online streaming — that's often been compared to that of the '90s juggernaut Friends. As of this writing, it is officially the longest-running multi-cam comedy series in television history and has earned over 50 Emmy Award nominations and 10 wins.

Of course, the longevity of The Big Bang Theory's success is due in no small part to its renowned ensemble cast, which has been anchored by Jim Parsons, Johnny Galecki, Kaley Cuoco, and co. since the show's 2007 debut. As their on-screen counterparts grew throughout the series, the performers themselves have also transformed before our very eyes. With the acclaimed comedy coming to an end in May 2019, let's take a look back to see just how much these fan-favorite actors have changed since their early appearances on The Big Bang Theory.

Mayim Bialik began playing Amy Farrah Fowler, a.k.a. Sheldon's perfect match, during season three of The Big Bang Theory. Previously best known as the titular child star of Blossom in the early '90s, Bialik actually shared her first on-screen kiss with none other than future TBBT co-star Johnny Galecki. She later took a temporary break from acting to pursue her PhD in Neuroscience at UCLA (via National Geographic). Her academic background has occasionally been helpful on the set of the CBS comedy, as her performance earned her four Emmy nominations.

Over the last decade, Bialik's continued to balance multiple hats in between acting jobs, including running a popular lifestyle blog called Grok Nation, authoring multiple parenting books, raising sons Frederick and Miles, and navigating two difficult breakups. However, it sounds like Bialik plans to ease into a post-TBBT world. "Am I happy? Of course not ... I love my job," she wrote about the show's impending ending in a 2018 blog post. Bialik added, "And now I start to figure out what next. Where will life take me? Where will this career go? What do I want?"

As the youngest member of The Big Bang Theory cast, Kaley Cuoco was just 21 when she landed the role of aspiring actress (and Leonard's love interest) Penny. While audiences may have recognized her for previous appearances on 8 Simple Rules and Charmed at the time, her career has since skyrocketed as she became one of the highest-paid actresses in TV. Following her failed high-profile romance with ex-husband Ryan Sweeting, Cuoco found love with equestrian Karl Cook, whom she married in June 2018.

Cuoco shows no signs of slowing down after the end TBBT. According to Deadline, she's set to star in and executive produce the TV movie The Flight Attendant through her company, Yes, Norman Productions. The actress-producer will also voice the titular character in the DC Universe animated series Harley Quinn. While discussing the end of the popular sitcom, Cuoco told People, "I can't really picture it. And I don't think there really will be my life without it — I think it'll always be there, I think it'll always be running, I think we'll always have those fans. It's always going to be a part of me."

Simon Helberg's run as aerospace engineer Howard Wolowitz on The Big Bang Theory began shortly after he tied the knot with actress Jocelyn Towne in 2007. According to Us Weekly, the couple have since welcomed daughter Adeline and son Wilder. While the actor already had over two-dozen on-screen credits to his name before landing TBBT, his multi-faceted career has since taken off exponentially. In addition to tying with co-star Nayyar as the third highest-paid actors in TV in 2018, he notably scored a Golden Globe nomination for his scene-stealing performance opposite Meryl Streep in 2016's Florence Foster Jenkins. 

With a blossoming film career in his back pocket, Helberg's first post-TBBT project will be a return to the stage in Witch (via Playbill), marking a strategic departure from his long-running portrayal of Howard. "It's like singing the same song for 12 years, and you can't even hear the song anymore. It doesn't even feel like exactly acting," he told The Los Angeles Times while rehearsing for another staged production in 2018. Of his pivot to live performance, he said, "it feels reminiscent of why I wanted to be an actor. Which was to play different characters and tell different stories."

Kevin Sussman is perhaps best known for portraying The Comic Center owner Stuart Bloom on The Big Bang Theory since season two. However, the actor previously played Walter on the ABC dramedy Ugly Betty and appeared in multiple cult-classics like Almost Famous, Wet Hot American Summer, and Burn After Reading. According to TV Line, he was promoted from his recurring role on TBBT to series regular in 2012. 

After finalizing his divorce from wife Alessandra Young in 2018, Sussman told City Press, "You know there is a blend there between Kevin-isms and Stuart-isms." Noting that he coincidentally used to work in a comic book store himself, the actor added, "Stuart is a more extreme version of me." While Sussman went on to jokingly propose a Stuart-centric spin-off series, his post-Big Bang Theory career may see more of a behind-the-scenes turn. According to Deadline, he and longtime TBBT co-star John Ross Bowie (who played Kripke) previously co-created two comedy pilots together: FOX's The Ever After Part and CBS' The Second Coming of Rob.