Here’s how that surprise The Big Bang Theory cameo in Young Sheldon season 4 premiere came to be. Season 3 of the prequel series was cut short by the coronavirus pandemic, so instead, they repurposed their intended finale to be this year’s first outing.
With Mary and George both agreeing that Sheldon is ready to go to college in Young Sheldon season 3, the new episode tackled them going through the motions of having him officially finish high school. That includes graduating early and at the top of his class. After doubting himself for a brief while, the young genius moves forward with their intended plan, with his family celebrating his and Missy’s graduation. That’s when narration from future Sheldon suddenly had The Big Bang Theory‘s Amy’s voice too as the pair playfully bicker about naming their son.
Young Sheldon creator Steve Molaro spoke to EW and broke down the surprise Mayim Bialik cameo, including how it came to be. As it turns out, the bit wasn’t part of the original script for the episode, but when the idea came up, they just had to do it. Fortunately, The Big Bang Theory actress agreed to participate, although she and Jim Parsons didn’t record their lines together. You can read Molaro’s exchange with EW, below.
This episode was intended to be the season 3 finale but then COVID shut down Hollywood. We were in the middle of shooting this as our finale. So the episode before it became the finale, which happened to work quite well. I always wanted to pick up right where we left off. Sheldon graduating is such a temporal moment. Why would we not give viewers that? Even CBS promoted it as the finale you didn’t get to see. Amy was not in the original draft from seven months ago, but when we were gearing up to shoot it, the opportunity presented itself. It seemed like a fun and nice way to check in with Sheldon and Amy. I gave Mayim a call and she was happy to do it. It turned out great. We don’t talk about it too much, but [the voiceovers are] Sheldon about 10, 11 years in the future.
Were Jim and Mayim together when they taped it?
They were not, they were not, but I mean, I know Jim and Mayim are still certainly friends in the real world.
Aside from Amy’s cameo, the Young Sheldon season 4 premiere also revealed her and Sheldon’s son who is interestingly named Leonard Cooper. As fans of The Big Bang Theory would know, there is a couple of important Leonards in Sheldon’s life. As a massive Star Trek fan, there’s Leonard Nimoy who played Spock. The voiceover revealed that Sheldon actually wanted to name their kid Leonard Nimoy Cooper but Amy objected. And then, of course, Leonard Hofstadter, Sheldon’s best friend who stuck with him through his worst tantrums and even when everyone else couldn’t deal with him anymore.
Bialik’s voice cameo marks the second time a The Big Bang Theory actor made an appearance on the show. In the season 3 episode titled “Teenager Soup and a Little Ball of Fib,” Sheldon dreams about speaking to the pool water before the swim test he’s dreading and it’s voiced by Penny actress, Kaley Cuoco. She was uncredited for the role, but fans immediately knew it was her voice; later on, it was officially confirmed. With Bialik and Cuoco already appearing in the prequel sitcom, it’s curious if Molaro and his team are planning to include any of the Pasadena gang into future Young Sheldon episodes. Perhaps Cuoco can also come back and reprise her role of Penny like Bialik did with Amy.