In 1977, University of Chicago students Sally Albright and Harry Burns arrange to share a ride to New York City, where Sally plans to study journalism and Harry will attend law school. While Sally waits impatiently in her car, Harry and his girl friend, Amanda Reese, engage in a prolonged goodbye kiss. Harry finally gets into Sally’s car and begins to snack on grapes. He mistakenly assumes the window is rolled down, spits out a grape seed, and it hits the glass. Disgusted, Sally refuses his offer of a grape, explaining that she does not eat between meals. As they get to know each other, Harry reveals his dark outlook on life, and they disagree over the ending of the film Casablanca. Sally insists that Ingrid Bergman’s character made the right choice by leaving Casablanca at the end of the movie, asserting that all women prefer stability over romance. The two stop for dinner, and Harry is amused by Sally’s picky way of ordering food. He compliments her on her good looks, but she takes offense, reminding him that he is dating her friend, Amanda. Returning to the car, Sally suggests that she and Harry become friends. However, Harry does not believe men and women can be friends, as “the sex part always gets in the way.” Sally laments that Harry was the only person she would have known in New York, and shakes his hand when they part ways in the city. Five years later, Sally kisses her boyfriend, Joe, at the airport. Harry interrupts, recognizing Joe from law school, but he cannot place Sally. She and Harry board the same flight, and he finagles the seat beside her after finally remembering her from the University of Chicago. Harry guesses that Sally and her boyfriend, Joe, are at an early stage in their relationship, and claims he would never take a girl friend to the airport to avoid setting a precedent. Sally is surprised to hear that Harry is engaged to a lawyer named Helen Hillson, with whom he claims to be madly in love. When they land, Harry invites Sally to dinner, but she reminds him of his theory that men and women cannot be friends. Harry argues that a friendship would work since they are both involved with other people, but contradicts himself by predicting their significant others would become jealous. The two part ways. Five years later, Sally meets her friends Marie and Alice for lunch and announces that she and Joe have broken up. The women are impressed by how well Sally is handling the heartbreak, but when Marie suggests setting her up on a date, Sally refuses. Elsewhere, at a football stadium, Harry tells his friend, Jess, that his wife, Helen, just left him for another man. Harry runs into Sally at a bookstore, and the two commiserate over their breakups. Sally asks him to dinner, and he asks, “Are we becoming friends now?” Soon, Harry and Sally’s friendship blossoms, and they begin to rely on each other for emotional support. When discussing their dating lives, Harry reveals that he sleeps with women even if he dislikes them, and Sally is appalled. At a batting cage, Harry’s friend, Jess, asks if he is attracted to Sally and likes to spend time with her, and Harry says yes. Jess does not understand why Harry refuses to become romantically involved with Sally, but Harry claims the friendship is helping his personal growth. At a delicatessen, Sally criticizes Harry’s casual approach to sex. He responds that the women he sleeps with have a good time, implying that they achieve orgasms when they are with him. Sally counters that women fake orgasms all the time, and when he does not believe her, she pretends to have one at the table. Moaning, shouting, and pounding on the tabletop, Sally draws everyone’s attention and prompts an older female patron to order whatever Sally is having. On New Year’s Eve, Harry and Sally go to a party, and Harry vows that if they are still single next year, he will be her date again. At midnight, they watch other couples kiss and give each other an awkward peck on the lips. Later, Harry and Sally set each other up with Marie and Jess on a double blind date. However, Marie prefers Jess over Harry, and vice versa, and the two hop into a cab together after dinner, leaving Harry and Sally alone. Four months later, while shopping for a housewarming gift for Marie and Jess, Harry and Sally run into Harry’s ex-wife, Helen. Upset by the encounter, Harry takes out his anger on Marie and Jess as they bicker over a coffee table in their new apartment. Sally leads Harry outside and discourages him from expressing every emotion he feels whenever he feels it. Harry accuses Sally of burying her emotions and reminds her that she has not slept with anyone since her ex-boyfriend, Joe. Hurt by the accusations, Sally tells Harry he sleeps with too many women, and he quickly apologizes, offering her a hug. Sometime later, Sally calls Harry in tears, relaying the news that Joe is getting married. Harry rushes over to Sally’s apartment. She cries on his shoulder, and he gives her a friendly kiss. She kisses him back, and the two make love. Afterward, Sally nuzzles Harry, while he lies nervously in her bed. In the morning, she wakes up to find him getting dressed. Before hurrying out, Harry asks Sally to dinner that night. The two spend the day fretting over what happened, and Sally announces at dinner that they made a mistake sleeping together. Harry is relieved. Later, Harry tells Jess that he and Sally must have passed a point in their relationship when it became too late to have sex. Weeks pass, and Harry and Sally are reunited at Marie and Jess’s wedding. Harry attempts to apologize, telling Sally he did not plan to make love to her when he went to her apartment, but he did not know how else to comfort her. She shouts at him for suggesting that he took pity on her and slaps him. Over Christmas, Sally ignores Harry’s phone calls. One day, he sings a song on her answering machine and she picks up. Harry apologizes, but Sally refuses to be his “consolation prize” when he asks her to be his date for New Year’s Eve. Sally goes to the New Year’s Eve party with Marie and Jess, but she cannot face the idea of being alone at midnight and decides to leave the party early. Meanwhile, Harry walks around the city, ruminating over his relationship with Sally. He runs to the party and finds Sally on her way out. Harry tells Sally he loves her, but she assumes he is only saying it because he is lonely. Harry lists off the personality traits that have endeared him to Sally and tells her that he wants to spend the rest of his life with her. Sally shouts that she hates Harry, then kisses him. Sometime later, Harry and Sally discuss their wedding, which took place three months later, and recall the coconut wedding cake served with chocolate sauce on the side, per Sally’s instructions.