<P> Penny is a fictional character on the American CBS sitcom The Big Bang Theory , portrayed by actress Kaley Cuoco . She is the primary female character in the series , befriending her across - the - hall neighbors Leonard Hofstadter ( Johnny Galecki ) and Sheldon Cooper ( Jim Parsons ) , two physicists who work at the nearby California Institute of Technology ( Caltech ) . Penny 's lack of advanced education , but outgoing personality and common sense drastically contrast with the personalities of the primary male characters in the series , even though she is considered part of their group . She is the love interest of Leonard , with whom she maintains a brief romantic relationship during the third season , which is later resumed in the fifth season and culminates in an engagement at the end of the seventh season and their wedding at the start of season 9 . Penny is the only main character of the show whose last name has not been revealed , although she has been occasionally referred to or addressed with the last name Hofstadter since her wedding . </P>
<P> Penny is a fictional character on the American CBS sitcom The Big Bang Theory , portrayed by actress Kaley Cuoco . She is the primary female character in the series , befriending her across - the - hall neighbors Leonard Hofstadter ( Johnny Galecki ) and Sheldon Cooper ( Jim Parsons ) , two physicists who work at the nearby California Institute of Technology ( Caltech ) . Penny 's lack of advanced education , but outgoing personality and common sense drastically contrast with the personalities of the primary male characters in the series , even though she is considered part of their group . She is the love interest of Leonard , with whom she maintains a brief romantic relationship during the third season , which is later resumed in the fifth season and culminates in an engagement at the end of the seventh season and their wedding at the start of season 9 . Penny is the only main character of the show whose last name has not been revealed , although she has been occasionally referred to or addressed with the last name Hofstadter since her wedding . </P>
who has played penny on the big bang theory
who has played penny on the big bang theory
Kaley Cuoco
Kaley Cuoco