George Steinbrenner was first mentioned on Seinfeld in the Season 4 episode, "The Smelly Car," when Kramer proclaimed that Steinbrenner's proclivity for trading away the Yankees' best prospects was ruining his life. But it would be a year later, at the end of Season 5, when George Costanza would get a job working for the Yankees and Steinbrenner would become a regular character on the best sitcom ever made.
But even though it was Seinfeld co-creator Larry David who voiced the Steinbrenner character, while an actor named Lee Bear was used to show the back of the owner's head, Steinbrenner actually became one of the most significant characters in Seinfeld's last few seasons. Often when characters would find themselves in precarious predicaments it was because of something related to Steinbrenner: When Costanza took a nap under his desk and didn't want Steinbrenner to find out, he had to call Jerry and ask him to phone in a bomb threat. When Costanza tried to convince a woman he had met that he was from Arkansas, Steinbrenner became convinced that Costanza was moonlighting for Tyler Chicken. When Costanza promised during a sexual encounter to give his secretary a raise, it was Steinbrenner who had to sign off on it. and so on.
The Steinbrenner character appeared on 16 episodes of Seinfeld, which makes him one of the most significant of the show's large cast of minor characters -- that's more than Uncle Leo, more than David Puddy, more than Kenny Bania, more than Jackie Chiles and more than Tim Whatley. Despite never appearing on camera, Steinbrenner will be remembered for playing a major role in one of the major television programs of 20th Century America.