Penelope "Penny" Hofstadter is a fictional character from the American CBS sitcom The Big Bang Theory, portrayed by actress Kaley Cuoco. She is the primary female character in the series, befriending her neighbors Sheldon Cooper (Jim Parsons) and Leonard Hofstadter (Johnny Galecki), two physicists employed at the California Institute of Technology (Caltech).

Penny's lack of education sets her apart from the group, and her outgoing personality and social aptitude drastically contrast with the personalities of the primary male characters in the series. She is the primary love interest of Leonard, who briefly dates her during the third season. This relationship is later resumed in the fifth season and culminates in their engagement at the end of the seventh season and their wedding at the start of season nine. Penny mentioned to Sheldon that she was aware that Leonard had "a tiny crush" on her after he first asked her out.