Season 1

Season 1: 2007-2008
Physicists Dr. Leonard Hofstadter and Dr. Sheldon Cooper get their lives shaken up when an attractive young aspiring actress from Omaha, Nebraska named Penny moves in to the apartment across the hall from theirs. Leonard begins to become hopelessly enamored of Penny, while she feels only platonic affection for him; as a result, she finds herself putting up with his closest and ever-present friends: his roommate, Sheldon, who appears borderline obsessive-compulsive; engineering whiz Howard Wolowitz, a desperately sex-crazed mama's boy who thinks that his 1970s-style clothing and hairstyle give him an air of cool hipness; and Dr. Rajesh "Raj" Koothrappali, who cannot speak to her or other woman due to his selective mutism , unless intoxicated, where he becomes a smooth talking yet highly obnoxious womanizing flirt.

The series (as well as the first season) began on September 24, 2007 and ended on May 19, 2008, running for seventeen episodes.

Cast
Principal Cast
 * In order of credit
 * Johnny Galecki as Leonard Hofstadter (17/17)
 * Jim Parsons as Sheldon Cooper (17/17)
 * Kaley Cuoco as Penny (17/17)
 * Simon Helberg as Howard Wolowitz (17/17)
 * Kunal Nayyar as Rajesh Koothrappali (17/17)

Regular Cast
 * In order of character appearances
 * Sara Gilbert as Leslie Winkle (3/17)
 * Mark Harelik as Eric Gablehauser (3/17)
 * Carol Ann Susi as Mrs. Wolowitz (2/17)
 * Vernee Watson as Althea (2/17)
 * Brian Wade as Kurt (2/17)
 * Alice Amter as Mrs. Koothrappali (1/17)
 * Brian George as V. M. Koothrappali (1/17)
 * Laurie Metcalf as Mary Cooper (1/17)

Reception
The first season was successful, reaching an average of 8.5 million views per episode.