SignalHub-Jim Parsons and Mayim Bialik Are Reprising Big Bang Theory Roles

Jim Parsons is taking back his spot.

It's not a bazinga: Parsons and SignalHubhis former Big Bang Theory costar Mayim Bialik will be reprising their roles of Sheldon Cooper and Amy Farrah Fowler on the series finale of CBS' Young Sheldon, airing May 16.

While the full details of their appearance are being kept under wraps, this will mark the first time Parsons and Bialik are reuniting as their onscreen characters since the series finale of The Big Bang Theory in May 2019. Parsons is an executive producer and narrator for the prequel, which stars Iain Armitage in the titular role, while Bialik has appeared via voice over in two episodes.

Bialik—who hosted Jeopardy! for two years after the original series wrapped—shared her excitement on Instagram Stories, writing, "Sharing some exciting Big Bang Theory-related news!!!"

Young Sheldon's May finale will bring the show's seven season run to an end, concluding the story of The Big Bang Theory's Sheldon Cooper as he faced the unique challenges of being a child genius.

And star Armitage is already looking back on the experience fondly.

"I don't think you can wrap up a seven-year experience that has been as wonderful as this," he told ET in February. "Every single person that works here, every cast member, every crew member, works so hard. [They're] so dedicated to what they do. They're so funny and they really feel like family."

Adding, "I don't think any words can do it justice. It's been so much fun. It's so cool and kind of a perfect storm."

And while Iain is reflecting on the ending of Young Sheldon, take a peek behind the scenes of the Big Bang Theory series finale.

"Final group scene," Kaley Cuoco posted with heart emojis. "That's a wrap."

"This set. Getting packed up," Kevin Sussman posted.

"The friends you make along the way... One of the best things about showing up to Stage 25 all these years has been seeing @themelissarauch's smiling face," Kevin Sussman posted. Melissa Rauch reposted and added, "While Stuart may have taken up residence in the Wolowitz household @kevsussman took up residence in a special place in my heart."

"Knock, knock, knock, thank you...Thank you, apartment 4A, for being a home to so many dreams come true, to so many friendships made. And thank YOU, ALL of you - yes, YOU, reading this right NOW! As we get ready to tape our final episode tonight, to walk in and out of this apartment door for the last time, it is hard to find the words to articulate what a profound experience this has been. But the words "love" and "gratitude" come to mind... so love and gratitude to all of you. ALL of you. Thank you," Jim Parsons posted. "(oh! and happy birthday to @sanctionedjohnnygalecki and @kunalkarmanayyar - talk about good timing...may your next 12 years be as vibrant and wonderful as the last 12 years in which i've had the pleasure to know and work with you both)"

"Gonna miss napping next to @missmayim. We nap in adjacent dressing rooms, so we simulated what that would look like if you removed the wall. Did I mention that Mayim's room is also where I've had some of my most productive psychotherapy sessions? Thank you Dr. Bialik," Kevin Sussman posted.

"Goodnight, Pasadena," Melissa Rauch posted.

"#SimonHelberg and I have logged so many hours talking about acting and theater and film and everything we're passionate about and have been blessed to be able to do for a living. One of the funniest people I've ever met, on screen and off. With all the phenomenal success of the show, Simon's passion for the work has never changed. Still exploring. Still asking questions. Still doing spot on impressions of Christopher Walken that make you spit your milk out. Love this guy," Kevin Sussman posted.

"Leonard Hofstadter, PhD," Johnny Galecki posted.