Early one morning, a taxi pulls up in front of Tiffany & Co. and from it emerges elegantly dressed Holly Golightly, carrying a paper bag containing her breakfast. After looking into its windows, she strolls to her apartment and has to fend off her date from the night before. Once inside, Holly cannot find her keys so she buzzes her landlord, Mr. Yunioshi, to let her in. Later, she is awakened by new neighbor Paul Varjak, who rings her doorbell to get into the building. The pair chat as she dresses to leave for her weekly visit to Sally Tomato, a mobster incarcerated at Sing Sing. Tomato’s lawyer pays her $100 a week to deliver “the weather report”.
As she is leaving, Holly is introduced to Paul’s “decorator”, wealthy older woman Emily Eustace Failenson, whom Paul nicknames “Tooley”. That night, when Holly goes out onto the fire escape to elude an over-eager date, she peeks into Paul’s apartment and sees Tooley leaving money and kissing him goodbye. Holly visits Paul later and learns he is a writer who has not had anything published since a book of vignettes five years before. Holly, in turn, explains she is trying to save money to support her brother Fred. The pair fall asleep but are awakened when Holly has a nightmare about her brother. When Paul questions her about this, Holly chides him for prying. She later buys Paul a typewriter ribbon to apologize and invites him to a wild party at her apartment. There, Paul meets her Hollywood agent, who describes Holly’s transformation from a country girl into a Manhattan socialite. He is also introduced to José da Silva Pereira, a wealthy Brazilian politician, and Rusty Trawler, the “ninth richest man in America under 50”.
The next day, Tooley enters Paul’s apartment, worried she is being followed. Paul tells her he will investigate and eventually confronts Doc Golightly, Holly’s estranged husband. Doc explains that Holly’s real name is Lula Mae Barnes and that they were married when she was approaching 14. Now he wants to take her back to rural Texas. After Paul reunites Holly and Doc, she informs Paul that the marriage was annulled. At the Greyhound bus station, she tells Doc she will not return with him, and he leaves broken-hearted.
After drinking at a club, Paul and Holly return to her apartment, where she drunkenly tells him that she plans to marry Trawler for his money. A few days later, Paul learns that one of his short stories will be published. On the way to tell Holly, he sees a newspaper headline stating that Trawler has married someone else. Holly and Paul agree to spend the day together, taking turns doing things each has never done before. At Tiffany’s, Paul has the ring from Doc Golightly’s box of Cracker Jack engraved as a present for Holly. After spending the night together, he awakens to find her gone. When Tooley arrives, Paul ends their relationship. She calmly accepts, having earlier concluded that he was in love with someone else.
Holly now schemes to marry José for his money, but after she receives a telegram notifying her of her brother’s death she trashes her apartment. Months later, Paul is invited to dinner by Holly, who is leaving the next morning for Brazil to continue her relationship with José. However, Holly and Paul are arrested in connection with Sally Tomato’s drug ring, and Holly spends the night in jail.
The next morning, Holly is released on bail. Paul is waiting for her in a cab, bringing her cat and a letter from José explaining that he must end their relationship due to her arrest. Holly insists that she will go to Brazil anyway; she asks the cab to pull over and releases the cat into the pouring rain. Paul then storms out of the cab, tossing the engraved ring into her lap and telling her to examine her life. She goes through a decision-making moment, puts on the ring and runs after Paul, who has gone looking for the cat. Finally, Holly finds it sheltering in an alley and, with it tucked into her coat, she and Paul embrace.