The mystery of what Penny’s last name is on The Big Bang Theory has remained even after the show ended. However, as it turns out, the series had already secretly revealed it very early on. As the only female character from the original sitcom, Kaley Cuoco’s Penny appeared in all 12 seasons of the CBS popular show. Although she seemed to stand out from her nerdy group of friends, she went through tremendous personal growth throughout those years, becoming one of the most popular characters in the series.
