Derek Thompson (Dwayne Johnson) is a minor league hockey player nicknamed the "Tooth Fairy" for hitting opposing players so hard that he knocks out their teeth. One night, Derek steals a dollar from his girlfriend Carly's (Ashley Judd) six-year-old daughter Tess (Destiny Whitlock) that had been left for her lost tooth and tells her that the tooth fairy doesn't exist. Then he receives a magical summons under his pillow. He grows wings and is transported to the realm of tooth fairies. He meets his case worker, Tracy (Stephen Merchant) and the head fairy, Lily (Julie Andrews). He has an adversarial relationship with them. Lily tells Derek that he is a "dream crusher," due to his unsympathetic dealings with children like Tess. He is sentenced to serve two weeks as a tooth fairy. Later, he meets Jerry (Billy Crystal), who gives him his tooth fairy supplies, which include "Shrinking Paste," "Invisible Spray," and "Amnesia Dust."
Carly's teenage son, Randy (Chase Ellison) dislikes Derek. Randy wants to grow up to be a heavy metal star. When Derek defends Randy against a bully, he begins to win him over, and Derek begins teaching him to play his electric guitar better so he can win a talent show.
Derek visits several children and tries his best to be a good tooth fairy, but ends up causing more harm than good. Lily says that he is the worst tooth fairy ever and denies him more supplies for the remainder of his sentence. He buys black market supplies from another fairy named Ziggy (Seth MacFarlane), but they malfunction and he is seen by a child's mother and arrested. While behind bars, Tracy tells Derek that his duty is extended to three weeks. Carly bails Derek out.
Despite managing to improve his tooth fairy skills, as well as bonding with Tracy and continuing to bond with Randy, this progress is halted when Derek becomes frustrated after he can't score a goal at a hockey game. He takes his anger out on Randy, telling him that he will never become a rock star. His dreams crushed, Randy smashes his guitar and Carly breaks up with Derek. Later, Tracy comes to Derek's house and announces that he is a tooth fairy in training, but that Derek's cruel remarks hurt himself more than others. The next game, Derek gets back on the ice and sees Tracy. Tracy wants to teach Derek the importance of dreams, encouraging Derek to score a goal and to go get Tess' tooth. With a renewed spirit, Derek scores the goal, gets into his tooth fairy costume, and flies away while Tracy spreads Amnesia Dust on the audience to cover up the event.
At Carly's, Tess sees Derek taking her tooth, but she promises to keep it a secret, and Derek apologizes to Randy and encourages him to keep pursuing his dreams, using his magic wand to grant Randy a new guitar. Downstairs, Carly sees him as a tooth fairy, but assumes that he rented a costume for Tess' sake, causing her to forgive him. Derek flies Randy to the talent show and throws Amnesia Dust on him when they arrive.
Derek heads back to the fairy realm to give Lily the tooth, and is told that because of this job, as well as reaffirming Tess' belief, he has been relieved of his fairy duties. Lily explains that he will never see the tooth fairies again and he will have Amnesia Dust thrown on him. Before departing, Derek says a friendly goodbye to Tracy. Lily throws Amnesia Dust on Derek and transports him back to the talent show. There, Randy outperforms everyone and ends up forming a band. Derek proposes to Carly, and she accepts.
During the credits, Derek is shown playing left wing for the Los Angeles Kings, and when he sees Jerry in the crowd, he doesn't recognize him. His fairy friends secretly help him score a goal.
The hockey scenes were filmed at the Great Western Forum. Many parts of the hockey games were based on the Vancouver Canucks using players from the Los Angeles Kings. The score for Tooth Fairy was composed by George S. Clinton and recorded in the spring of 2009 with an 80-piece ensemble of the Hollywood Studio Symphony at the Newman Scoring Stage at 20th Century Fox studios.
The film was released on January 22, 2010, and opened in 8 theaters and took in $3,544,512 its opening day, with an average of $1,060 per theater. On its opening weekend, it grossed $14,010,409 with an average of $4,190 per theater. It ranked #4, behind Avatar, Legion, and The Book of Eli; however, the film rose to #3 on that weekend in Canada with $16,000,000 and remained #4 in the U.S. on its second weekend, behind Avatar, Edge of Darkness, and When in Rome. Despite negative reviews, the film has come to be a box office hit grossing $60,022,256 in the United States and Canada, and $51,854,764 in other markets, grossing a worldwide total of $111,877,020.
The film has received negative reviews from critics. Review aggregation website Rotten Tomatoes gives a score of 18% based on 113 reviews, with an average rating of 4/10. The site's consensus states: "Dwayne Johnson brings the full force of his charm (and his appropriately pale chompers) to the title role, but flat direction and a committee-written script render The Tooth Fairy unacceptably dull". Metacritic, which assigns a weighted average score out of 0–100 reviews from film critics, has a rating of 36% based on 24 reviews, which indicates "generally unfavorable reviews".
Tooth Fairy was released on DVD and Blu-ray Disc/DVD/Digital copy combination pack on May 4, 2010.
Tooth Fairy was followed up by a sequel, starring Larry the Cable Guy as the title character. Directed by Alex Zamm, Tooth Fairy 2 had a direct-to-video release on March 6, 2012.