List of The Big Bang Theory characters

The American television sitcom The Big Bang Theory, created and executive produced by Chuck Lorre and Bill Prady, premiered on CBS on September 24, 2007.

The series initially centers on five characters: roommates Leonard Hofstadter and Sheldon Cooper, two Caltech physicists; Penny, a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's friends and co-workers aerospace engineer Howard Wolowitz, and astrophysicist Raj Koothrappali.

Over time, several supporting characters have been introduced and promoted to starring roles, including Leslie Winkle, Amy Farrah Fowler, Bernadette Rostenkowski-Wolowitz, Stuart Bloom, and Emily Sweeney. The series also features numerous supporting characters, each of whom plays a prominent role in a small group of episodes. Included among them are parents of the main characters, their dates and their coworkers. Celebrities such as Stephen Hawking occasionally appear in cameo roles as themselves.

Leonard Leakey Hofstadter (Johnny Galecki) is an experimental physicist with an IQ of 173. Originally from New Jersey, he received his PhD at age 24, spending at least some of his time at Princeton University. He shares an apartment in Pasadena with colleague and friend Dr. Sheldon Cooper. Unlike his equally geeky friends, Leonard is interested and quite adept in building interpersonal and social relationships with other people. Compared to his friends, he is relatively successful with women.

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