<Ul> <Li> Johnny Galecki as Leonard Hofstadter : An experimental physicist with an IQ of 173 , who received his PhD when he was 24 years old . Leonard is a nerd who loves video games , comic books , and Dungeons & Dragons . Leonard is the straight man of the series , in which he shares an apartment in Pasadena , CA , with Sheldon . Leonard is smitten with his new neighbor Penny when they first meet , and they eventually marry . </Li> <Li> Jim Parsons as Sheldon Cooper : Originally from Galveston , Texas , Sheldon was a child prodigy with an eidetic memory who began college at the age of eleven , and earned a PhD at age sixteen . He is a theoretical physicist researching quantum mechanics and string theory , and despite his IQ of 187 , he finds many routine aspects of social situations difficult to grasp . He is determined to have his own way , continually boasts of his intelligence , and has an extremely ritualized way of living . Despite these quirks , he begins a relationship with Amy Farrah Fowler , they are now engaged to marry . </Li> <Li> Kaley Cuoco as Penny : An aspiring actress from Omaha , Nebraska . Penny moves in across the hall from Sheldon and Leonard . She waits and occasionally tends the bar at the Cheesecake Factory . After giving up hope of becoming a successful actress , Penny becomes a pharmaceutical sales representative . Penny becomes friends with Bernadette and Amy , and they often hang out in each other 's apartments . Penny and Leonard form a relationship and eventually marry . </Li> <Li> Simon Helberg as Howard Wolowitz : An aerospace engineer . Howard is Jewish and lives with his mother , Debbie ( Carol Ann Susi ) . Unlike Sheldon , Leonard , Raj , Bernadette and Amy , Howard does not hold a doctorate . He goes into space , training as an astronaut and serving as a payload specialist . Howard initially fancies himself as a womanizer , but he later starts dating Bernadette , and they get engaged and married . Howard also has a tendency to waste money on toys and argues with Bernadette because of his oddly low income as an engineer and her high income as a pharmaceutical biochemist . </Li> <Li> Kunal Nayyar as Rajesh Koothrappali : A particle astrophysicist originally from New Delhi , India . Raj is initially unable to talk to women unless he drinks alcohol . Raj also has very feminine tastes and often takes on a stereotypical female role . Raj later dates Lucy ( Kate Micucci ) , who also suffers from social anxiety , but it eventually ends ; he later speaks to Penny without alcohol and thus overcomes his selective mutism . He begins dating Emily and their relationship later becomes exclusive . Raj also has a Yorkshire Terrier named Cinnamon . </Li> </Ul>
<Ul> <Li> Johnny Galecki as Leonard Hofstadter : An experimental physicist with an IQ of 173 , who received his PhD when he was 24 years old . Leonard is a nerd who loves video games , comic books , and Dungeons & Dragons . Leonard is the straight man of the series , in which he shares an apartment in Pasadena , CA , with Sheldon . Leonard is smitten with his new neighbor Penny when they first meet , and they eventually marry . </Li> <Li> Jim Parsons as Sheldon Cooper : Originally from Galveston , Texas , Sheldon was a child prodigy with an eidetic memory who began college at the age of eleven , and earned a PhD at age sixteen . He is a theoretical physicist researching quantum mechanics and string theory , and despite his IQ of 187 , he finds many routine aspects of social situations difficult to grasp . He is determined to have his own way , continually boasts of his intelligence , and has an extremely ritualized way of living . Despite these quirks , he begins a relationship with Amy Farrah Fowler , they are now engaged to marry . </Li> <Li> Kaley Cuoco as Penny : An aspiring actress from Omaha , Nebraska . Penny moves in across the hall from Sheldon and Leonard . She waits and occasionally tends the bar at the Cheesecake Factory . After giving up hope of becoming a successful actress , Penny becomes a pharmaceutical sales representative . Penny becomes friends with Bernadette and Amy , and they often hang out in each other 's apartments . Penny and Leonard form a relationship and eventually marry . </Li> <Li> Simon Helberg as Howard Wolowitz : An aerospace engineer . Howard is Jewish and lives with his mother , Debbie ( Carol Ann Susi ) . Unlike Sheldon , Leonard , Raj , Bernadette and Amy , Howard does not hold a doctorate . He goes into space , training as an astronaut and serving as a payload specialist . Howard initially fancies himself as a womanizer , but he later starts dating Bernadette , and they get engaged and married . Howard also has a tendency to waste money on toys and argues with Bernadette because of his oddly low income as an engineer and her high income as a pharmaceutical biochemist . </Li> <Li> Kunal Nayyar as Rajesh Koothrappali : A particle astrophysicist originally from New Delhi , India . Raj is initially unable to talk to women unless he drinks alcohol . Raj also has very feminine tastes and often takes on a stereotypical female role . Raj later dates Lucy ( Kate Micucci ) , who also suffers from social anxiety , but it eventually ends ; he later speaks to Penny without alcohol and thus overcomes his selective mutism . He begins dating Emily and their relationship later becomes exclusive . Raj also has a Yorkshire Terrier named Cinnamon . </Li> </Ul>
the original cast of the big bang theory
the original cast of the big bang theory
Johnny Galecki as Leonard Hofstadter Jim Parsons as Sheldon Cooper Kaley Cuoco as Penny Simon Helberg as Howard Wolowitz Kunal Nayyar as Rajesh Koothrappali
Johnny Galecki as Leonard Hofstadter Jim Parsons as Sheldon Cooper Kaley Cuoco as Penny Simon Helberg as Howard Wolowitz Kunal Nayyar as Rajesh Koothrappali