Seinfeld was a television show.
Cosmo Kramer , usually referred to as simply `` Kramer '' , is a fictional character on the American television sitcom Seinfeld ( 1989 -- 1998 ) , played by Michael Richards . Larry Charles . Charles is best known as a staff writer for the American sitcom Seinfeld for its first five seasons , contributing some of the show 's darkest and most absurd storylines . Seinfeld is an American sitcom that originally ran for nine seasons on NBC , from 1989 to 1998 . Set predominantly in an apartment building in Manhattan 's Upper West Side in New York City , the show features a handful of Jerry 's friends and acquaintances , particularly best friend George Costanza ( Jason Alexander ) , former girlfriend Elaine Benes ( Julia Louis-Dreyfus ) , and neighbor across the hall Cosmo Kramer ( Michael Richards ) .