The original The Big Bang Theory sitcom ran for 12 seasons. It premiered on CBS on September 24, 2007, and concluded on May 16, 2019, with 279 episodes across its full run.
The series was created by Chuck Lorre and Bill Prady and initially followed physicists Sheldon Cooper and Leonard Hofstadter, their friend Howard Wolowitz, astrophysicist Raj Koothrappali, and their neighbor Penny. Amy Farrah Fowler and Bernadette Rostenkowski later became central members of the ensemble.
The twelfth season was also the final season. CBS and Warner Bros. Television announced the ending in 2018 after Jim Parsons decided not to continue as Sheldon. That season contained 24 episodes and ended with the characters resolving major personal and scientific storylines, including Sheldon and Amy receiving the Nobel Prize in Physics.
A common mix-up is confusing the show's 12 seasons with its 279 episodes or with Young Sheldon, its prequel, which ran for seven seasons. The Big Bang Theory remains one of television's longest-running multi-camera sitcoms.