Larry David famously instituted a policy of "no hugging, no learning", meaning that the show must avoid sentimentality and moral lessons, and the characters must never learn or grow from their wrongdoings.
Jerry Seinfeld turned down an offer from NBC that would have made him $110 million for a tenth season of the show.
It was originally intended that Elaine's formidable father, famous author Alton Benes of whom Jerry and George are terrified, be a recurring character, but in an odd case of life imitating art, veteran character actor Lawrence Tierney really did so frighten and intimidated the other cast members that it was decided he should never return.
Jerry says "Hello, Newman" only 16 times in the entire series.
Before the show was set to air, Jerry Seinfeld asked Jason Alexander what he thought their chances for success were. Alexander said he thought they "didn't have a chance." When asked why, Alexander responded, "Because the audience for this show is me, and I don't watch TV."
The Soup Nazi is based on the actual owner, Al Yeganeh, of a take-out soup business in Manhattan on West 55th Street between Broadway and 8th Avenue. Just like in the sitcom, his soups were known for their excellent quality, but Yeganeh was also famous for the unusual way he treated his customers. Instead of calling him a Nazi, local patrons called him a terrorist, presumably because they knew Yeganeh was born in Iran, not Germany. Yeganeh was so angered by the episode that he forbid the use of the "N word" in his restaurants. Even the slightest reference to "Seinfeld" would push his buttons (it can be seen in an interview he did with CNN). So when some cast members and writers from "Seinfeld" bravely visited the restaurant after the episode aired, Yeganeh claimed that the show had ruined his life.
Jason Alexander is the only actor of the four main-characters to not win an Emmy.
In the episode where Elaine dates a man named Joel Rifkin, she tries to have him change his name, since Joel Rifkin is also the name of a man involved in a notorious New York City murder case. One of the initial suggestions for a new name was O.J. This episode was shot in 1993, a year before O.J. Simpson was accused of murdering his ex-wife Nicole Brown Simpson and Ron Goldman.
The puffy shirt used in "The Puffy Shirt" episode is currently placed in the Smithsonian. A doll-sized replica was included with the fifth season DVD set.
Kramer's wardrobe of mostly 1960s and 1970s clothing was not intended to make him into retro fashions, so much as to suggest that he hadn't bought clothes in several years. The pants in particular were always about an inch too short in order to stress this. In later seasons, appropriate clothing became increasingly difficult for producers to find, due to the combination of it getting older and older as well as the extreme popularity of Kramer as a character, forcing them to have tailors personally make Kramer's clothing out of retro fabrics. Often, they would create numerous back-up copies of the clothing in case it was damaged during the physical comedy.
The restaurant exterior belongs to Tom's Restaurant, which is the same restaurant that was immortalized in the Suzanne Vega song "Tom's Diner." It is near the Columbia University campus in Manhattan at West 112th Street and Broadway.
Voted the #1 top TV series of all time, beating out #2, I Love Lucy (1951), and #3, The Honeymooners (1955), in the list of 50 shows chosen by TV Guide editors, April 2002.
Kramer's line "These pretzels are making me thirsty" is an homage to Jeff Goldblum and his one and only line in "Annie Hall" a Woody Allen film. Goldblum's line is famous in movie history for his delivery.
In the episode "The Watch", Elaine (played by Julia Louis-Dreyfus) is asked by Joe Davola if he knows her from somewhere and she answers with a joke: that he probably recognizes her because her face is sculptured on Mount Rushmore, alongside the U.S. presidents, instead of Roosevelt's face. Way later, on 2015, a poster was released for the fourth season of the HBO series Veep, that shows the face of Selina Meyer (who's played by Julia Louis-Dreyfus), sculptered on Mount Rushmore, but it appears instead of Jefferson's face.
Ranked #11 on Empire magazine's 50 Greatest TV Shows Of All Time (2008).
In 2013, the Writers Guild of America named Seinfeld the No. 2 Best Written TV Series of All Time (second to The Sopranos). That same year, Entertainment Weekly named it the No. 3 best TV series of all time and TV Guide ranked it at No. 2.
The lexicon of Seinfeldian code words and recurring phrases that evolved around particular episodes is referred to as Seinlanguage, the title of Jerry Seinfeld's best-selling book on humor.