Belle Williams (Queen Latifah) is a talented driver and auto mechanic who dreams of driving in NASCAR. As the film opens, she celebrates her last shift as a bicycle courier after winning her taxi license and beating the shop's record with a new delivery record of 13 minutes and 54 seconds. Although in a happy relationship, she occasionally neglects her boyfriend Jesse (Henry Simmons) and has bestowed much love on her custom-built 1999 Ford Crown Victoria taxicab over the past five years. She skips her dinner date, to install a supercharger that was given to her as a present for her last day.
The next day, her first customer offers her a $100 tip if she can make it to JFK Airport in fifteen minutes. She makes it in 9 minutes and 28 seconds, while almost getting caught speeding on the freeway and through Manhattan. Meanwhile, a group of beautiful women exit the airport, with a man waiting for them.
The action cuts back to New York City where bumbling undercover detective Andy Washburn (Jimmy Fallon) is about to bust a phone card ring from Cuba. He makes up a street name in Havana, which blows his cover, and a gunfight develops. Washburn's partner is wounded in the arm and the Cubans escape. Trying to follow them in his partner's car, he reverses it into a store, killing the detective's parrot. Back at the precinct station, Lt. Marta Robbins (Jennifer Esposito) confiscates his driver's license and demotes him indefinitely to foot patrol duty.
Later, hearing of a bank robbery, Washburn tries to flag down a car in the middle of a street, causing dozens of civilians and their cars to crash into each other, resulting in a major pileup. He flags down a taxicab, which turns out to be Belle's. He commandeers the car which transforms into the street car from earlier. They arrive at the bank just as the four robbers leave in a BMW. Washburn accidentally shoots out one of Belle's windows and they end up cornering the BMW in an alley. The BMW driver cleverly gives Belle the slip, but as the car passes, she recognizes the occupants as the same models from the airport. Their leader is Vanessa (Gisele Bündchen). In a misunderstanding, police arrive and hold up Belle and Washburn.
Belle's cab is impounded as evidence and she is taken in for questioning as a witness to the robbery; she is upset as it means the loss of two weeks' earnings. Washburn promises to get her cab back if she will join him on his beat—thus solving the problem of his confiscated license.
Belle and Washburn pursue the robbers, getting close once or twice. Washburn takes Belle to his home. Washburn's mother (Ann-Margret) is constantly drunk and always has a batch of margaritas going in the blender. She brings up embarrassing moments of Washburn's past and talks about why he's such a bad driver.
Later, Washburn talks to the impound cop (Patton Oswalt) and eventually convinces him to give him and Belle the cab back. They realize that the gang always robs banks just before the garbage collection is due. The robbers take the money, put it in the trash and the garbage man collects it. However, because of constantly disobeying orders, he is fired. Later that night, Belle teaches him to drive with "This Will Be (An Everlasting Love)" playing on the radio. They discover the garbage collector on the bank route has been performing collections for the gang because they have kidnapped his wife. They trace the kidnapper and recover the garbage collector's wife and all the loot.
The police learn which bank is next to be hit, and they lie in wait for the robbers, who take a hostage. After a hostage swap, the gang escapes with Lt. Robbins as hostage, followed by Washburn and Belle in her cab. Belle calls on the help of her former bike messengers to pinpoint the location of the car. Using the cash from the garbage truck, they pinpoint the operation HQ and negotiate a trade. Belle transforms the cab and during the ensuing chase, they continually try to swap the hostage for the money while driving down the highway. Washburn forces the robbers down a long bridge he knows is under construction. With the robbers trapped on a section of the long bridge, Washburn and Belle laugh victoriously. Enraged, Vanessa fires her gun at them and wounds Belle. Washburn drives Belle to the hospital singing "This Will Be (An Everlasting Love)."
In the final scene, Belle is in NASCAR, fulfilling her dream, sponsored by New York banks. Washburn (recently reinstated back into the NYPD), Lt. Robbins and Washburn's mother cheer her on. Jesse makes his proposal to Belle. Jeff Gordon, driver of the 24 car in NASCAR's top series, makes an appearance.Queen Latifah as Isabelle "Belle" Precious WilliamsJimmy Fallon as Det. Andy WashburnGisele Bündchen as VanessaHenry Simmons as JesseJennifer Esposito as Lt. Marta RobbinsAna Cristina de Oliveira as Redhead (Second Robber)Ingrid Vandebosch as Third RobberMagali Amadei as Fourth RobberAnn-Margret as Washburn's MomChristian Kane as Agent MullinsBoris McGiver as FranklinAdrian Martinez as Brazilian ManJoe Lisi as Mr. Anthony ScaliaGQ as Stopwatch MessengerBryna Weiss as Mrs. ScaliaJohn Krasinski as MessengerJeff Gordon as himself (cameo appearance)
While the film was a financial success, grossing almost three times its budget, it was panned by critics. The review aggregator Rotten Tomatoes reports that only 10% of critics gave the film a positive review based on 105 reviews, showing the film's negative reviews despite its financial success. Roger Ebert described it as "dismal" and "wall-to-wall idiocy". Despite this, Taxi was released on October 6, 2004 in 3,001 theaters and opened at #4 at the box office. It grossed $12,029,832 in the opening weekend. It went on to gross $36,611,066 domestically and a further $32,284,369 from foreign markets contributed to a worldwide total of $68,895,435. Its budget, meanwhile, was $25 million.