When Harry Met Sally... is a 1989 American romantic comedy film directed by Rob Reiner and written by Nora Ephron. Starring Billy Crystal, Meg Ryan, Carrie Fisher, and Bruno Kirby, it follows the title characters from the time they meet in Chicago and share a drive to New York City through twelve years of chance encounters in New York, and addresses the question "Can men and women ever just be friends?"

Ideas for the film began when Reiner and Penny Marshall divorced. An interview Ephron conducted with Reiner provided the basis for Harry; Sally was based on Ephron and some of her friends. Crystal came on board and made his own contributions to the screenplay. Ephron supplied the structure of the film with much of the dialogue based on the real-life friendship between Reiner and Crystal. The soundtrack consists of standards from Harry Connick Jr., with a big band and orchestra arranged by Marc Shaiman. For his work on the soundtrack, Connick won his first Grammy Award for Best Jazz Male Vocal Performance.

Columbia Pictures released When Harry Met Sally in selected cities, letting word of mouth generate interest, before gradually expanding distribution. The film grossed $92.8 million in North America, and was released to critical acclaim. Ephron received the BAFTA Award for Best Original Screenplay, as well as nominations for the Academy Award, WGA Award and Golden Globe. The film is ranked 23rd on AFI's 100 Years... 100 Laughs list of the top comedy films in American cinema and number 60 on Bravo's "100 Funniest Movies". In early 2004, the film was adapted for the stage in a production starring Luke Perry and Alyson Hannigan. In 2022, the film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".

In 1977, Harry Burns and Sally Albright graduate from the University of Chicago. Harry is dating Sally's friend Amanda Reese, leading to Harry and Sally ride-sharing to New York City. Sally is attending journalism school there and Harry has a job waiting.

During the drive, Harry and Sally discuss their differing ideas about relationships; Sally disagrees with Harry's assertion that men and women cannot be friends as "the sex part gets in the way". They stop at a diner, and when Harry tells Sally she is very attractive, she angrily accuses him of making a pass. They part company in New York, never intending to see each other again.

Five years later in 1982, Harry and Sally find themselves on the same flight. Sally is dating Harry's neighbor Joe, and Harry is engaged to Helen, which surprises Sally, as it seems uncharacteristically optimistic of him. Harry suggests they become friends, forcing him to qualify his previous position about the impossibility of male-female friendships. They separate, concluding that they will not be friends.

Five years later in 1987, Harry and Sally run into each other at a bookstore. They have coffee and talk about their previous relationships; Sally and Joe have broken up and Helen has left Harry for another man. They agree to pursue a friendship and have late-night phone conversations, go to dinner, and spend time together discussing their love lives.

During a New Year's Eve party, Harry and Sally find themselves growing attracted to each other and share an awkward midnight kiss. They remain friends and set each other up with their respective best friends, Marie and Jess. When the four go out, neither Marie nor Jess is attracted to Harry or Sally and instead immediately fall for each other. Soon after, the two are engaged.