Is Hayley Kiyoko On The Big Bang Theory? A Viral Mistake Explained

Names are tricky. We've all gotten that one friend of a friend confused with that C-list actor your other friend told you about once. Sometimes, you run across two names so similar that no amount of dedicated brain time can sufficiently unjumble them. That's probably why, even now, to this day, people are still out here thinking that Hayley Kiyoko starred in "The Big Bang Theory."

She played Penny, right? Hayley Kiyoko? No, see, that's Kaley Cuoco. Hayley Cuoco? Kaley Kiyoko? No, again: Kaley Cuoco — star of "The Big Bang Theory," voice of Harley Quinn, and producer extraordinaire — and Hayley Kiyoko — former child star, queer icon, and dream pop sensation. To this day, people get the two confused, and it's easy to see why. The names are just too easy to mix up. And while Kiyoko is certainly better known these days for her music career, she hasn't entirely left acting behind.

Apparently, the mix-ups have made their way back to the stars themselves. Back in 2021, Kiyoko made a TikTok post spoofing the phenomenon, writing in the caption, "This happens more than you'd think." So, for the sake of clarity, let's take a look at the two multi-hyphenates in question, how their careers have been similar, and where they diverge.

Hayley Kiyoko is six years younger than Kaley Cuoco, but they both started acting early. Kiyoko first appeared in a series of commercials when she was young and later popped up across Nickelodeon and Disney Channel. In 2009, she played Velma Dinkley in the live-action TV movie "Scooby-Doo! The Mystery Begins" — a role she reprised a year later in "Scooby-Doo! Curse of the Lake Monster." In 2019, she wrapped up a 20-episode run on "Five Points." For years, Kiyoko has focused more on her music, as well as directing music videos and publishing a novel.

Cuoco also began her onscreen career at a young age, popping in background television roles as early as 1992, when she was only seven years old. She got her break in the early 2000s when she was cast as Bridget Hennessey on ABC's "8 Simple Rules," which was accompanied by more notable parts in projects like "Charmed" (as Billie Jenkins) and "Bratz" (as Kirstee). It wasn't until "The Big Bang Theory" started in 2007, though, that Cuoco was launched from working actor to superstar. Ever since the series came to an end, she's been producing work through her company Yes, Norman Productions, which helped yield the incredible "Harley Quinn" animated series on Max.

Both stars have achieved significant success, rising up from humble beginnings in kids' programming to become true owners of their own unique brands.