Seinfeld’s main starring cast consisted of four actors: Jerry Seinfeld, Jason Alexander, Julia Louis-Dreyfus, and Michael Richards.
Seinfeld played a fictionalized version of himself. Alexander portrayed his anxious best friend George Costanza, Louis-Dreyfus played Jerry’s ex-girlfriend Elaine Benes, and Richards played eccentric neighbor Cosmo Kramer.
The number can be confusing because the series featured a large and memorable supporting ensemble. Recurring performers included Wayne Knight as Newman, Estelle Harris and Jerry Stiller as George’s parents, and Liz Sheridan and Barney Martin as Jerry’s parents. Those actors were important to the show but were not part of its four-person main starring cast.
Elaine was not in the original pilot, “The Seinfeld Chronicles,” but became one of the central characters after her introduction. The four regulars ultimately appeared together throughout the show’s best-known ensemble era, spanning nine seasons and 180 episodes from 1989 to 1998.