The film was produced by Caravan Pictures and DIC Entertainment (which was owned by The Walt Disney Company at the time of production) and distributed by Walt Disney Pictures on July 23, 1999. It was filmed in Pittsburgh, Pennsylvania, Baton Rouge, Louisiana, and Los Angeles, California, with the ice castle-like main tower of Pittsburgh's PPG Place playing a central role. This was the last film produced by Caravan Pictures before it merged into Spyglass Entertainment. This film was dedicated to the memory of production designer Michael White who died on January 19, 1999 in Los Angeles during production of the film at the age of 36. The film was a moderate box office success with a worldwide gross of $134.4 million against a $90 million budget despite receiving negative reviews from critics. It was followed by the 2003 direct-to-video stand-alone sequel Inspector Gadget 2.
Jonathan "John" Brown is a security guard working at the Bradford robotics laboratory in Riverton, Ohio, run by Artemus Bradford and his daughter Brenda, to whom John is attracted. Brenda and Artemus create a lifelike robotic foot as part of the Gadget Program, an organization for manufacturing computerized law enforcement officers. Sadistic tycoon Sanford Scolex attacks the lab, steals the foot, and has Artemus murdered before escaping in his limo. Brown chases him down in his Chevette and in the ensuing chase Scolex blows up the upside down wreck and leaves John for dead. A bowling ball coming from the blast of the Chevette crushes Scolex's hand, forcing him to replace it with a mechanical claw and taking the alias "Claw."
John barely survives the explosion, and due to his devotion to pursuing her father's killer, Brenda chooses him to be the first test subject for the Gadget Program. Under Brenda's guidance, John becomes Inspector Gadget, equipped with a variety of crimefighting and investigating tools, as well as a car named the Gadgetmobile run by an AI program. Claw, with the help of scientist Kramer and minion Sykes, plots to use the technology he stole to make robotic mercenaries to sell to the world. However he is unable to get the foot to function due to a control chip left in the lab. Police chief Quimby, seeing Gadget as merely a publicity stunt and not a true police officer, refuses to let him help on the Bradford case, causing Gadget to procure evidence on his own. With help from Penny, Gadget suspects Claw, who Brenda now works for. Claw uses Brenda's robotics research to manufacture a new control chip for his android, a robotic version of Gadget, "Robo-Gadget," and sets it loose to cause chaos in Riverton. Gadget infiltrates Claw's lab but is caught and deactivated, Claw crushing his control chip.
Brenda, Penny, her dog Brain, and the Gadgetmobile track Gadget to the junkyard but find him unresponsive. Brenda kisses him, and the power of Gadget's heart reanimates his body without the need for the control chip. After dropping Penny and Brain off at home, Gadget, Brenda and the Gadgetmobile give chase to Claw's limo. Gadget and Robo-Gadget are thrown off and do battle, ending with Gadget detaching Robo-Gadget's head. Gadget uses his helicopter hat to fly to Claw's headquarters, where he is planning to escape with Brenda via a helicopter. In the confrontation, Gadget uses an improvised weapon to forcibly activate Claw's claw, breaking the helicopter's control stick and causing it to go out of control. Gadget and Brenda use a parasol to escape safely, and Claw lands via parachute but is arrested by the police. Penny arrives with a guilt-stricken Sykes who surrenders the technology Claw stole from Brenda and has told Penny everything about Claw's plans. Saluted by Quimby, Gadget departs with Brenda and Penny as Claw vows revenge.
During the end credits, several afterscene clips play, including Sykes going to a minion-recovery group, and the Gadgetmobile addresses the audience till the end of the credits.
During the "Minions Anonymous" scene in the credits, the henchmen include Mr. T and Richard Kiel (who is credited as the "Famous Bad Guy with Silver Teeth", in reference to his role of James Bond's enemy Jaws), as well as Richard Lee-Sung as the "Famous Villain with Deadly Hat", Bobby Bell as the "Famous Identifier of Sea Planes", Hank Barrera as the "Famous Native American Sidekick", and Keith Morrison as the "Famous Assistant to Dr. Frankensomething". Broderick and Coleman previously worked together in the film WarGames.
Universal Pictures at one point had an option on the film rights to the animated television series in 1993. Ivan Reitman signed on to produce with a script by Jeph Loeb and Matthew Weisman. Inspector Gadget moved to Disney when the film studio bought out DIC Entertainment. Disney hired David Kellogg to direct, best known for "The Adventures of Seinfeld & Superman" TV commercials and the Vanilla Ice film, Cool as Ice (1991).
Cameron Diaz declined the role of Dr. Brenda Bradford in favor of Any Given Sunday.
Brendan Fraser was considered for the role of Inspector Gadget, but turned it down on account of working on George of the Jungle, another live-action Disney film based on an animated cartoon. Kevin Kline was also considered for the role.
Steven Spielberg, a fan of the 1980s cartoon, considered being the film's executive producer. His two choices for the role of Inspector Gadget were Chevy Chase and Steve Martin, but he was too busy with other films such as Saving Private Ryan.
Lindsay Lohan turned down the role of Penny, due to her working on her first film, The Parent Trap.
Tim Curry was considered for the role of Doctor Claw.
Louis C.K. auditioned for a role as a police officer.
After a test screening, the film was cut to 78 minutes from the original 110-minute version.
The Gadgetmobile, designed by Brenda Bradford, is a white & chrome 1964 Lincoln Continental convertible instead of a Matra Murena/Toyota Celica hybrid from the cartoon and can't transform from a minivan to a police vehicle and often drives by itself. It has an artificial intelligence with a male persona. Like most anthropomorphic cars, "his" front bumper is his mouth and he has eyes in his headlights. However, unlike those cars, who have two eyes, he has four. He also has a face on a computer screen on the dashboard and a license plate that reads "GADGET". Among other things, he can camouflage himself, has a radar system to track Gadget's location (and other people's as well), can extend his tires upwards, has retractable jail bars in his back seat (for transporting criminals), a vending machine (options on this include Skittles, M&M's, Sprite, Coca-Cola and McDonald's), sirens in the hood that attach to the windshield, and a jet engine he keeps in his trunk. His artificial intelligence has a laid-back personality. The Gadgetmobile openly breaks the law constantly (he is a particular fan of backturns), but claims it is okay: "Speed limits are for cars, not the Gadgetmobile." Comedian D. L. Hughley provides his voice.
The soundtrack of the film, composed by John Debney, contains the single "I'll Be Your Everything" by the boy band Youngstown.
Inspector Gadget was released on VHS and DVD December 7, 1999, and re-released on DVD May 27, 2003 by Buena Vista Home Entertainment.
On Rotten Tomatoes, the film has a rating of 21%, based on 62 reviews, with the consensus reading: "Despite an abundance of eyecandy, the film doesn't amount to much." Metacritic reports a rating of 36 out of 100, based on 22 critics, indicating "generally unfavorable reviews".
Lawrence Van Gelder of The New York Times stated that it "wastes a lot of good talent". In his review for the Chicago Sun-Times, Roger Ebert mentioned that fans were angered when Dr. Claw reveals himself in the movie.
The film was a moderate box office success with a worldwide gross of $134.4 million worldwide, against a budget of $90 million. In its opening weekend, the film grossed $21.9 million, finishing in second at the box office behind The Haunting ($33.4 million). In the United Kingdom, it grossed just over £7 million.
In May 2015, it was announced that a new film with a rebooted version of the character is currently in development.