‘Big Bang Theory’ Star Kaley Cuoco Reveals the Last Name the Cast Made up for Penny

The Big Bang Theory ended in 2019 but it still has secrets to uncover. Kaley Cuoco has moved on to a new show, the HBO Max drama The Flight Attendant. Even she is still revealing new information about her character Penny. 

Big Bang Theory five
L-R: Simon Helberg, Kunal Nayyar, Jim Parsons, Johnny Galecki and Kaley Cuoco | Sonja Flemming/CBS via Getty Images

Cuoco was a guest on the HFPA In Conversation podcast on Dec. 11 promoting The Flight Attendant. When host Kristen Gijbels asked about The Big Bang Theory, they discussed theories about Penny’s last name. 

Why ‘The Big Bang Theory’ never gave Penny a last name 

The story goes that Cuoco was added to the pilot after test audiences reacted poorly to the original female character. Rewriting the female lead, the writers named her Penny. Just Penny. 

The Big Bang Theory creator Chuck Lorre suggested she is Penny Barrington, but Barrington was never spoken on the show so it is not canon. 

Kaley Cuoco and Johnny Galecki
Kaley Cuoco and Johnny Galecki | Sonja Flemming/CBS via Getty Images

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After Penny proved to be a hit, the writers became superstitious about Penny’s lack of a last name. They never wanted to tempt fate by adding a last name. That meant that even by season 12, Cuoco’s character was just Penny. Like Cher or Madonna. That has led fans to speculate on what Penny’s last name was, that is before she became Mrs. Leonard Hofstadter.

Kaley Cuoco hears one theory for the first time 

Gijbels asked Cuoco about her favorite theory. She thinks Cuoco’s character was Penny Wyatt, because her father’s name was Wyatt. This would assume that people called her father by his last name, as Americans tend to do. Cuoco could not confirm this theory, but it suitably amused her.

“Wyatt?” Cuoco said. “I have never heard that. I couldn’t be because really her dad’s name is Wyatt so how would it be Wyatt? This is the first time I’ve ever heard that. That is hilarious. That’s brilliant.”

Kaley Cuoco’s favorite ‘Big Bang Theory’ Penny theory 

Cuoco has her own favorite theory about Penny’s last name. Sheldon (Jim Parsons) would alway cross the hall and knock on her door, calling her name three times. Cuoco supports the theory that he knew something nobody else knew. 

Big Bang Theory trio
L-R: Kaley Cuoco, Melissa Rauch and Mayim Bialik | Sonja Flemming/CBS via Getty Images

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“There was a really funny [theory] that her name was Penny Penny Penny and the only person that knew that from the beginning was Sheldon,” Cuoco said. “That’s why he always knocked on her door like that. It was like, ‘Wait a minute, that’s been your name?’ And Sheldon’s like, ‘Yeah, that’s why I’ve knocked on the door.’ He did that with everybody but we all thought that was funny to think about that he would’ve known the entire time.”

Kaley Cuoco still misses ‘The Big Bang Theory’

Cuoco is embarking on a brand new journey with The Flight Attendant, but she still misses The Big Bang Theory. 

Going into these other things, like Flight Attendant, whatever I’m doing, I really have accepted that nothing will be like Big Bang. That really for me is in a lane all its own. THere’s nothing that I could do or would want to do to compare anything to that. It was so special in so many ways as far as just the unbelievable cast and the crew and the 12 years of work and the pay and all these different things that were truly incomparable. I do feel like we’re one of the last traditional multicam live audience sitcoms. I don’t know how much longer those are going to be around and I’m so glad I was part of that show.

Kaley Cuoco, The HFPA In Conversation podcast, 12/11/2020