It was filmed in Rome, Lazio, Italy, and at the Trevi Fountain. The film was released in early May 2003 and reached number two in the United States box office. It was released August 12, 2003 on VHS and DVD.
During the junior high graduation, Lizzie McGuire (Hilary Duff) is forced to make a speech in place of the class president, Margaret Chan, where she trips on stage, and brings the curtain down on everyone who is onstage. She and her friends then leave on a class trip to Rome for two weeks, accompanied by her rude and strict new high school principal Ms. Ungermeyer (Alex Borstein) and her ex-best friend Kate Sanders.
After discovering she is sharing a room with Kate, Ms. Ungermeyer takes them to the famous Trevi Fountain where Lizzie throws a penny into the water for good luck. This causes several bystanders to trip. A few seconds later, she meets the famous European pop star, Paolo (Yani Gellman), who exclaims how much she resembles his singing partner, Isabella (also played by Hilary Duff). Paolo promises to meet Lizzie at the Trevi Fountain the next day if Lizzie wishes to see him again. The next day, Lizzie pretends to be sick and sneaks off to meet Paolo. She goes on a drive with him, agreeing to sing with him as Isabella to prevent Isabella from being sued for lip-synching. Later, Lizzie discovers that she also has to lip-synch "What Dreams Are Made Of", but agrees to do that too. Kate finds out the truth but helps Lizzie instead.
Lizzie continues to pretend to be sick, but when her scheme is about to be discovered, Gordo sacrifices himself by telling Ms. Ungermeyer that he was the one who was sneaking out. Just as he's about to board the plane home, he meets the real Isabella at the airport and discovers the truth about Paolo. Gordo and Isabella race to the music event to stop Paolo from making a fool of Lizzie on stage. Paolo's plan was to show the world that Isabella is lip-synching; ironically, it turns out that Paolo was lip-synching. Isabella and Gordo expose Paolo by pulling the plug on his microphone, causing him to be shown for the fake he actually is. Lizzie then ends up singing "What Dreams are Made of" in front of the entire audience inside the Colosseum.
Later at the hotel, Paolo's ex-bodyguard, Sergei, has formed a new relationship with Ms. Ungermeyer. Ms. Ungermeyer is informed of the truth about Lizzie sneaking off and Gordo earns her respect as a loyal friend to Lizzie. Lizzie and Gordo sneak away for the last time from the after-party and went up to the roof to talk. Gordo reassures Lizzie that things will be just as good when they go back home and that he always believes in her. Then, Lizzie gives him a kiss and he says "thanks". They both decide to go back to the afterparty before they get in trouble again. So, they both return to the after party as the fireworks spell out the words "The End".
- Hilary Duff as Elizabeth "Lizzie" Brooke McGuire, the film's main protagonist/Isabella Parigi, Paolo's ex-girlfriend and singing partner
- Adam Lamberg as David "Gordo" Gordon, Lizzie's best friend and the deuteragonist
- Robert Carradine as Sam McGuire, Lizzie's father
- Hallie Todd as Jo McGuire, Lizzie's mother
- Jake Thomas as Matthew "Matt" McGuire, Lizzie's mischievous younger brother
- Yani Gellman as Paolo Valisari, a handsome, famous Italian pop star and the film's antagonist who plans to use Lizzie to avoid getting sued for breach of contract
- Alex Borstein as Miss Ungermeyer, the abrasive and strict school principal who chaperones the trip
- Clayton Snyder as Ethan Craft
- Ashlie Brillault as Katherine "Kate" Sanders, Lizzie's arch-rival who ends up helping Lizzie
- Brendan Kelly as Sergei, Paolo's bodyguard who eventually quits and forms a relationship with Ms. Ungermeyer
- Carly Schroeder as Melina Bianco
- Daniel R. Escobar as Mr. Escobar
- Jody Racicot as Giorgio
- Terra MacLeod as Franca DiMontecatini
- Haylie Duff as Isabella Parigi (voice) uncredited
- Claude Knowlton as Stage Manager
Ultimate Disney reviewed the DVD saying "I didn't expect much from this movie and would have never paid to see it, but maybe I should have because it's a great movie for what it is. I can forgive and forget the corny scene when she's singing at the end, since the rest of the movie makes up for it. I highly recommend this movie to anyone who watches and enjoys the TV series; it's like a feature-length show. If you're not familiar with the show, it's a nice feel-good movie you should check out. Gus' Movie Score (1 to 10): 81⁄2 (Italian cinema reference intended? You be the judge.)"
Scott Brown of Entertainment Weekly magazine gave the film a B+ and commented in his review saying "Let's face it: Lizzie McGuire (Hilary Duff) is just too darn polished to be a junior-high underdog, even by the standards of her 'luxe suburban environs'. But that hasn't tarnished her comeback-kid cred among the six-and-ups who faithfully follow her Disney Channel show — and it doesn't make The Lizzie McGuire Movie, a clever, agreeably weightless theatrical outing, any less enjoyable."
In its opening weekend, the film grossed $17,338,755 in 2,825 theaters in the United States and Canada, ranking #2 at the box office, behind X2: X-Men United, was the best debut for an Walt Disney and Teen comedy film that week. By the end of its run, The Lizzie McGuire Movie grossed $42,734,455 domestically and $12,800,000 internationally, totaling $55,534,455 worldwide.
- 2004 - Nominated; Leo Awards for Feature Length Drama: Best Visual Effects (Gary Gutierrez, Jayne Craig, Bruce Woloshyn, Simon Ager, Wes Sargent)
- 2003 - Won; Teen Choice Awards for Choice Movie Breakout Star - Female (Hilary Duff)
- 2003 - Nominated; Teen Choice Awards for Choice Movie - Comedy
- 2003 - Nominated; Teen Choice Awards for Choice Movie Actress - Comedy (Hilary Duff)
The Lizzie McGuire Movie is a soundtrack album for the film, released on April 22, 2003.
It is mostly composed of songs from or inspired by the film, including Hilary Duff's "Why Not" and sister Haylie's "Girl in the Band". "Why Not" was released as a single outside the United States on June 23, 2003 and later included on Hilary Duff's second album, Metamorphosis, with different lyrics in the first verse. The album has been certified platinum by the CRIA and 2x platinum by the RIAA has sold 2,000,000 copies in the U.S,