In 1995, Jackie Brown, a middle-aged flight attendant for a small Mexican airline, makes ends meet smuggling money from Mexico into the United States for Ordell Robbie, a black-market gun runner living in the Los Angeles metropolitan area. Ordell is under close watch by the ATF, forcing him to use couriers. When he learns that another of his couriers, Beaumont Livingston, has been arrested, he assumes Livingston will become an informant to avoid jail time. Ordell arranges for bail with bondsman Max Cherry, then coaxes Livingston into a car trunk and murders him.
Acting on information Livingston had already shared, ATF agent Ray Nicolette and LAPD detective Mark Dargus intercept Jackie as she returns to the United States with Ordell's cash and some cocaine that Brown was unaware was stashed in her bag. Initially refusing to cut a deal, she is sent to jail, which alerts Ordell that she might also be a threat to inform. Having received payment from Ordell, Max picks up Jackie from the jail and begins to develop an attraction to her. Ordell arrives at Jackie's house intending to murder her, but she surprises him by pulling a gun surreptitiously taken from the glove compartment of Max's car. Jackie negotiates a deal with Ordell to pretend to help the authorities while smuggling in $550,000 of Ordell's money, enough to allow him to retire.
To carry out this plan, Ordell is counting on Melanie Ralston, an unambitious, pot-smoking surfer girl with whom he lives, and Louis Gara, a friend and former cellmate. Unaware of Jackie and Ordell's plan to smuggle in $550,000, Nicolette and Dargus devise a sting to catch Ordell during a transfer of $50,000. Unbeknownst to all, Jackie plans to double-cross everyone and keep $500,000 for herself. She recruits Max to assist with her plan and offers him a cut.
In the Del Amo Fashion Center on the day of the transfer, Jackie enters a dressing room to try on a new suit. She has told Ordell that she will swap bags there with Melanie, supposedly passing off the $550,000 under the nose of Nicolette, who has been told that the exchange is to take place in the food court. Instead, the bag she gives Melanie contains only $50,000 and she leaves the rest behind in the dressing room for Max to pick up. Jackie then feigns despair as she calls Nicolette and Dargus out from hiding, claiming Melanie took all the money and ran.
In the parking lot, Melanie snobbishly mocks Louis until he loses his temper and shoots her to death. Louis confesses this to Ordell. Ordell is livid when he discovers that most of the money is gone, and he realizes that Jackie is to blame. When Louis mentions that during the hand-off he saw Max Cherry in the store's dress department and thought nothing of it, Ordell kills Louis and leaves with the bag. Ordell turns his anger toward Max, who informs him that Jackie is frightened for her life and is waiting in Max's office to hand over the money. A menacing Ordell holds Max at gunpoint as they enter the darkened office. When Jackie yells that Ordell has a gun, Nicolette jumps from a hiding place and kills him.
With the ATF dropping charges for her cooperation, Jackie takes the remainder of Ordell's money and his car. She decides to leave the country and travel to Madrid, Spain. She invites Max to go along with her, but he declines. Jackie shares a meaningful moment with Max, kisses him goodbye, and leaves as Max takes a phone call. Moments later, Max cuts the call short and contemplates his decision to stay behind as Jackie drives away.