Professor Philip Brainard (Robin Williams), an absent minded professor, works with his robot assistant Weebo (voiced by Jodi Benson), trying to create a substance that's a new source of energy and that will save Medfield College where his sweetheart Dr. Sara Jean Reynolds (Marcia Gay Harden), the remake's version of Betsy Carlisle, is the dean. He has missed his wedding twice, and on the afternoon of his third wedding, Brainard accidentally creates Flubber, which allows objects to fly through the air. It behaves like rubber, so he calls it Flubber (Flying Rubber). When he misses the third wedding, he tries to explain it to Sara by demonstrating flubber, but he falls out a window and Sara angrily breaks up with him and begins seeing Wilson Croft (Christopher McDonald), a professor from another college and the remake's version of Alonzo Hawk.
Meanwhile, Brainard creates a flying car to win Sara back and tries to figure out ways to control the Flubber. He comes up with an idea to use the Flubber to help the Medfield basketball team win the championship, which they do, but he doesn't win Sara's heart back. Back at the house, he explains to Weebo that he's absent-minded because he's in love with Sara and Weebo records him saying it. She goes to Sara's house to prove it to her. Brainard then wakes up to see her standing above him and she kisses him.
At the same time, a rich and corrupt businessman named Chester Hoenicker (Raymond J. Barry) wants Phillip to pass his failing son Bennett (Wil Wheaton), but he soon takes an interest in Flubber after hearing about it from his flunkies Smith (Clancy Brown) and Wesson (Ted Levine). Smith and Wesson steal the Flubber and destroy Weebo in the process. Brainard and Sara get the Flubber back in a battle.
At last, Flubber is accidentally swallowed by Wilson, making him suffer from "inside" his body to the outside, making him "dancing", being tiklish, laughing, and moving around. Inside him, Flubber makes a short "body controlling awkard dancing/tiklish sensation" "journey", through his digestive system, that makes Whim suffer and laugh, every last second. Once he wants to fart Flubber, he calls for "his mommy", farts it painfully, while it goes out of his body (like a bullet), laughing, and flying away. After that, Wilson looks at the others (Doctor and Sara) and faints, exhausted and half-dead. Brainard and Sara, which are shocked out by seeing the effect of swallowing Flubber, they go out of the room.
(Since that, nobody knows how to explain briefly and better what happened with Wilson, his body, his digestive system, after and before Flubber came into his body. All we know it's that is an awkward scene that Disney will never reveal.)
The film end with Sara and Phillip flying away in the autocar with Weebo's daughter, Weebette, in the trunk having finally married through a video screen (similar to Skype).
- Robin Williams as Professor Philip Brainard
- Marcia Gay Harden as Dr. Sara Jean Reynolds
- Christopher McDonald as Wilson Croft
- Raymond J. Barry as Chester Hoenicker
- Clancy Brown as Smith
- Ted Levine as Wesson
- Wil Wheaton as Bennett Hoenicker
- Edie McClurg as Martha George
- Leslie Stefanson as Sylvia
- Malcolm Brownson as Father
- Benjamin Brock as Window Boy
- Dakin Matthews as Minister
- Zack Zeigler as Teenage Boy
- Sam Lloyd as Coach Willy Barker
- Scott Michael Campbell as Dale Jepner
- Bob Sarlatte as Rutland Coach
- Bob Greene as Referee
- Tom Barlow as Medfield Basketball Player
- Scott Martin Gershin as Flubber
- Jodi Benson as Weebo
- Frank Welker as Rover
- Julie Morrison as Weebette
- Weebo (voiced by Jodi Benson) is a floating robot in yellow, black, and gray, served as Brainard's assistant. She has eyes that have a different shape and possesses light. When she expresses, she shows segments of many actions and feelings from her LCD screen when it opens. For example, she shows the segment that has Doc from Disney's Snow White and the Seven Dwarfs sleeping in a sink. Throughout the movie, she prevents Brainard from marrying Sara due to the fact that, she herself, is in love with Brainard. She also can make a holographic projection in the form of a human spirit (with a white dress on it) from her screen but she sees that Brainard and Sara are made for each other and goes to tell Sara. The moment before her death, she also has a great time with Flubber. She was later hit by a baseball bat (courtesy of Wesson) while trying to protect the flubber, dies and also gives Brainard the blueprints for her daughter Weebette.
- Webber (voiced by Campbell Morton) is a Helping Robot in Gray He gives breakfast for Philip Brainard and also cleans up the house.
- Flubber (voiced by Scott Martin Gershin) is a green substance accidentally created by Philip Brainard. It can move, bounce, form shapes and even dance very comically. After Weebo takes a picture of it and Brainard, it uncontrollably begins to bounce around causing trouble to the neighbors. It also helped the Squirrels win a game. Also in the end, one of the flubbers decided to join Brainard, his wife, and Weebette in the flying car.
- Weebette (voiced by Julie Morrison), like her mother Weebo, is a floating robot in red and black. In the end of the movie, Weebette joined Brainard and Sara in the flying car, along with a hitchiking Flubber saying she does not want to share a bunk with him and calling him disgusting.
Flubber performed well at the box office. It made $92,977,226 in the United States, and a total of $85 million in other countries for a grand total of $178 million internationally.