Monk’s Diner is the name of the restaurant featured on Seinfeld. Monk’s is one of the most popular locations in the series, appearing in almost every episode. The diner never really has much to do with the plots of the show, it’s just the default location for the gang to go to discuss their lives. They always sit and the same table and they hate sitting at the counter.

George always orders a tuna on toast (until he orders the opposite of that, which is apparently chicken on rye) and he thinks that the mirror in the bathroom sort of makes him look like Robert Wagner. The back booth at Monk’s is also the only place where Jerry’s two-face girlfriend always looked good. Kramer has dated several girls who worked the cash register there. The head cook is an imposing man named Larry (who is also in charge of enforcing the diner's strict "No outside syrups, jams, or condiments" policy), but the actual restaurant is owned by Mr. Papanikolas, who employs his many buxom daughters as waitresses. Paco, one of the other cooks, is known to drop rubber bands into people's soup.

In the pilot episode the restaurant was called Pete’s Luncheonette and Claire, the mean waitress, was the female lead on the show instead of Elaine.

The exterior shot used in the show is of Tom’s Restaurant located at 113th and Broadway in Manhattan. This place was also the inspiration for a Suzanne Vega song.