Seinfeld is an American sitcom that originally ran for nine seasons on NBC, from 1989 to 1998. It was created by Larry David and Jerry Seinfeld, the latter starring as a fictionalized version of himself. Set predominantly in an apartment building in Manhattan's Upper West Side in New York City (although taped entirely in Los Angeles), 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). It is often described as being "a show about nothing", as many of its episodes are about the minutiae of daily life.

Seinfeld was produced by Castle Rock Entertainment. In syndication, the series has been distributed by Sony Pictures Television since 2002. It was largely written by David and Seinfeld with script writers who included Larry Charles, Peter Mehlman, Gregg Kavet, Carol Leifer, David Mandel, Jeff Schaffer, Steve Koren, Jennifer Crittenden, Tom Gammill, Max Pross, Dan O'Keefe, Charlie Rubin, Marjorie Gross, Alec Berg, Elaine Pope, and Spike Feresten.

A favorite among critics, the series led the Nielsen ratings in seasons six and nine, and finished among the top two (with NBC's ER) every year from 1994 to 1998. In 2002, TV Guide named Seinfeld the greatest television program of all time. In 1997, the episodes "The Boyfriend" and "The Parking Garage" were respectively ranked numbers 4 and 33 on TV Guide's 100 Greatest Episodes of All Time, and in 2009, "The Contest" was ranked No. 1 on the same magazine's list of TV's Top 100 Episodes of All Time. E! named it the "number 1 reason the '90s ruled." 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.