The film is a film-within-a-film, wherein Kermit the Frog and the rest of the Muppets create havoc in a screening room where they are about to watch The Muppet Movie. When asked by Robin if the film depicts how the Muppets began, Kermit responds that the movie is a somewhat fictionalized account. As the story opens, Kermit is enjoying a relaxing afternoon in a Florida swamp, singing a tune (the Oscar-nominated "The Rainbow Connection") and strumming his banjo, when he is approached by an agent named Bernie (Dom DeLuise) who recognizes his talents and encourages Kermit to pursue a career in Hollywood. Inspired by the idea of "making millions of people happy," Kermit sets off on a cross-country trip to Hollywood, initially via bicycle but eventually via Studebaker after teaming with Fozzie Bear, who had been working as a hapless stand-up comedian in a sleazy bar, whose owner and pianist are cameoed by James Coburn and Paul Williams respectively. During their journey, they are pursued by the villainous Doc Hopper (Charles Durning, speaking with a Southern accent and wearing an outfit similar to Colonel Sanders), owner of a struggling French-fried frog legs restaurant franchise, and his shy assistant, Max (Austin Pendleton). Doc Hopper wants Kermit to be the new spokesman for his restaurants, but when Kermit refuses, Hopper refuses to accept "No" for an answer and resorts to increasingly threatening means of persuasion.
Kermit and Fozzie's journey also includes misadventures which introduce them to a variety of eccentric characters, some played by human guest stars, others played by Muppets ("Moving Right Along"). During one of their drives, they encounter Big Bird and offer him a ride. Big Bird declines stating that he's heading to New York City to make a debut on public television. Kermit and Fozzie Bear encounter Dr. Teeth and The Electric Mayhem and their manager Scooter who plan to turn an abandoned church into a coffee house. They manage to disguise Kermit's car so that Doc Hopper can't recognize them ("Can You Picture That?"). Kermit and Fozzie end up encountering Gonzo and Camilla the Chicken who had been working as plumbers until their truck crashes into Kermit and Fozzie's car. When it comes to getting a replacement car from a used car dealer owner Mad Man Mooney (Milton Berle), they meet Sweetums and invite him to join them. Sweetums runs off and Kermit drives away unbeknownst that Sweetums has left to pack his things. At a carnival, the group meets Miss Piggy following a beauty contestant, who falls in love with Kermit in the process ("Never Before, Never Again"). She joins Kermit and Fozzie as they rescue Gonzo, who floats away in the sky with a bunch of balloons. Sweetums is still trailing Kermit. At a local motel, Kermit and Miss Piggy formed a relationship during dinner, but an insolent waiter calls Miss Piggy for the telephone, causing her to abandon Kermit at the motel alone and depressed. Kermit wanders into the bar and meets Rowlf the Dog, who works as a pianist at a lounge and cheers him up by telling him about the difficulty of having to live with and without women ("I Hope That Somethin' Better Comes Along"). Doc Hopper and Max kidnap Miss Piggy and Doc sends a call to Kermit to exit the motel where Kermit runs into Doc's henchmen because Doc Hopper said that if Kermit didn't, Miss Piggy would be slaughtered. Doc Hopper has hired a mad scientist named Professor Max Krassman (Mel Brooks) in an attempt to brainwash Kermit. Fortunately, the scientist insults Miss Piggy just before he starts the process, causing her to break free in a rage and defeat him and Doc Hopper's henchmen. Immediately after freeing Kermit, Miss Piggy gets a call from her agent about a job and promptly abandons Kermit at the barn alone and heartbroken.
Following a problem with the film, the movie continues as Kermit's group is now joined by Rowlf ("America"), and then rejoined by Miss Piggy. Meanwhile, Doc Hopper goes to an even further scheme by hiring an assassin named Snake Walker (Scott Walker) who kills frogs for a living. Doc Hopper broadcasts on the CB Radio threatening for Kermit to surrender and agree to Doc Hopper's deal or he will become a frog burger. When night falls, Kermit's car breaks down leaving the group stranded in the desert. During a campfire that night, they sadly consider that they may miss the audition tomorrow, and Gonzo cheers up most of the group with a song about his longing to find his place in the world ("I'm Going to Go Back There Someday"), while Kermit wanders off, ashamed of himself for seemingly bringing his friends into a dead end, and wondering whether his dreams were really worth leaving home for. Upon consulting a more optimistic vision of himself, Kermit remembers that it was not just his friends' belief in the dream that brought them this far, but also his own faith in himself. Kermit hears music and returns to the camp where Electric Mayhem and Scooter arrive in their bus having followed the script that Kermit left behind and end up taking them to Hollywood.
The next day, Max appears to Kermit disguised as a motorcycle policeman to warn Kermit that Doc Hopper has hired the assassin to kill Kermit. Refusing to be hunted any longer, Kermit attempts a Western-style showdown the restaurant owner in a ghost town where the group meets Dr. Bunsen Honeydew and his assistant Beaker (who owns a laboratory in a ghost town). Kermit breaks tradition by trying to talk Hopper into backing off, but Hopper refuses and orders his henchmen to kill him and all his friends. Kermit is saved only when one of Dr. Bunsen's inventions, "insta-grow" pills, temporarily turn Animal into a giant who is able to permanently scare off Hopper and his men (Animal is later shrunken back down to his normal size in the next scene since the effect of the pills is only temporary).
The Muppets proceed to Hollywood, where they finally meet the imposing producer and studio executive Lew Lord (Orson Welles) (a reference to Lord Lew Grade who in real life gives The Muppet Show the green light), and hires them on the spot under "the standard rich-and-famous contract" after Kermit reveals why they've come. The film ends with Kermit and the gang attempting to make their first movie, which turns out to be a surreal pastiche of their experiences, hinting that the movie they're making is the same one the audience has been watching all along ("The Magic Store"), but a huge stage accident occurs causing most of the props to collapse and fall, and cause the lights to explode. As the dust around shattered roof clears, a stream of rainbow appears, and the Muppets joined in by other Muppet characters, the characters from Sesame Street, and the characters from "The Land of Gorch" segment of Saturday Night Live sing one last reprise of "Rainbow Connection", ending the film.
After the end title appears, Sweetums tears through the screen "finally" having caught up with the others to the amusement of the audience who then talk amongst each other as the credits roll. After the credits finish rolling, Animal tells the viewers to go home, then he says goodbye and passes out.
- Austin Pendleton as Max
- Charles Durning as Doc Hopper
- Scott Walker as Snake Walker
- Lawrence Gabriel, Jr. as a sailor
- Ira F. Grubman as a bartender
- H.B. Haggerty as a lumberjack
- Bruce Kirby as a gate guard
- Tommy Madden as One-Eyed Midget
- James Frawley as a writer
- Arnold Roberts as a cowboy
Cameo Guest Stars
- Edgar Bergen as Himself and the voice of Charlie McCarthy
- Milton Berle as Mad Man Mooney
- Mel Brooks as Professor Max Krassman
- James Coburn as the owner of El Sleezo Cafe
- Dom DeLuise as Bernie the Agent
- Elliott Gould as a Beauty Contest Compere
- Bob Hope as an Ice Cream vendor
- Madeline Kahn as a patron at El Sleezo
- Carol Kane as Myth
- Cloris Leachman as Lord's Secretary
- Steve Martin as an insolent waiter
- Richard Pryor as Balloon Vendor
- Telly Savalas as El Sleezo Tough
- Orson Welles as Lew Lord
- Paul Williams as the pianist at El Sleezo
- Jim Henson as Kermit the Frog, Rowlf the Dog, Dr. Teeth, Waldorf, The Swedish Chef
- Frank Oz as Miss Piggy, Fozzie Bear, Animal, Sam the Eagle
- Jerry Nelson as Floyd Pepper, Crazy Harry, Robin the Frog, Lew Zealand, Camilla the Chicken
- Richard Hunt as Scooter, Statler, Janice, Sweetums, Beaker
- Dave Goelz as The Great Gonzo, Zoot, Dr. Bunsen Honeydew
- Caroll Spinney as Big Bird
- John Landis as Grover (uncredited)
- Link Hogthrob, Fletcher Bird, Mean Mama, Luncheon Counter Monster, Blue Frackle, Baskerville the Hound, Nigel (Muppet Show), Pigs
The Muppet Movie uses meta-references as a source of humor, as characters occasionally break the fourth wall to address the audience or comment on their real-life circumstances:
- Fozzie: [to Big Bird] "Hey, there! Wanna lift?"
- Big Bird: "Oh, no thanks. I'm on my way to New York City to try to break into public television."
(This refers to Big Bird's future "career" on Sesame Street.)
In a particularly meta-fictional plot twist, Kermit and Fozzie actually give the screenplay to Dr. Teeth, who later uses it to find and rescue them after they have been stranded in the desert.
Filming locations included Albuquerque, New Mexico and Los Angeles, California.
To perform Kermit static on a log, Jim Henson squeezed into a specially designed metal container complete with an air hose (to breathe), a rubber sleeve which came out of the top to perform Kermit and a monitor to see his performance, and placed himself under the water, log, and the Kermit puppet. He was also assisted in this operation by Kathryn Mullen and Steve Whitmire. This scene took five days to film.
Several classic cars were specially selected by Henson for appearances in the film. The most famous was a pair of psychedelic painted 1951 Studebaker Commander Coupes. In the film, Fozzie states that he inherited the car from his uncle. When asked by Kermit if his uncle is dead, Fozzie replies "no, he's hibernating". One car was painted but unmodified and driven by a person in the front seat. It was used for long, traveling shots. The second car was driven by a person in the trunk, who viewed the road through a TV set. The TV received its image from a camera located in the center nose of the car's front grill. This made it possible for Frank Oz to sit in the front seat and portray Fozzie driving the car in close up shots. This car is now on display at the Studebaker Museum in South Bend, Indiana.
Doc Hopper is chauffeured throughout the movie by Max in a 1959 Cadillac Fleetwood Limousine. The 1959 is distinctive for its enormous fins. The final car driven by the Muppets is a 1946 Ford 'Woody' Station Wagon, which is famous for its wood panel siding and is a valuable collectible.
The Muppet Movie received positive reviews; as of July 5, 2015, the film holds an 89% "Certified Fresh" rating on Rotten Tomatoes, based on 47 reviews and an 8/10 rating, which indicates "generally favorable reviews", at Metacritic. Roger Ebert gave it three-and-a-half out of four stars. He stated, "The Muppet Movie not only stars the Muppets but, for the first time, shows us their feet." The film sold nearly 26 million tickets and grossed $65,200,000 domestically (adjusted for inflation, this would equal $206,509,960 in 2010 dollars), making it the highest-grossing Muppet film. The success of the film gave The Jim Henson Company an opportunity to release more Muppet productions theatrically, all of which were successful.
In 2009, it was named to the National Film Registry by the Library of Congress for being “culturally, historically or aesthetically” significant and will be preserved for all time.
The film's soundtrack was released by Atlantic Records in 1979, and on CD by Jim Henson Records in March 1993. The songs were written by Paul Williams and Kenny Ascher. Williams recalled to Songfacts: "Jim Henson gave you more [creative] freedom than anybody I've ever worked with in my life. I said, 'You want to hear the songs as we're writing them?' He said, 'No. I'll hear them in the studio. I know I'm gonna love them.' You just don't get that kind of freedom on a project these days."
"Movin' Right Along", "Never Before, Never Again" and "I Hope That Somethin' Better Comes Along" were shortened in the film, compared to their soundtrack versions, for continuity purposes. The latter, a duet between Rowlf and Kermit, contained references that the studio considered too mature for children. In "Finale: The Magic Store", a line performed by Kermit in the film is sung by Fozzie on the soundtrack recording.
Several of the songs were included The Muppet Show: Music, Mayhem, and More - The 25th Anniversary Collection released in 2002.
- "The Rainbow Connection" - Kermit
- "Moving Right Along" - Kermit and Fozzie
- "Never Before, Never Again" - Miss Piggy
- "Never Before, Never Again" (Instrumental)
- "I Hope That Somethin' Better Comes Along" - Kermit and Rowlf
- "Can You Picture That?" - Dr. Teeth and the Electric Mayhem
- "I Hope That Somethin' Better Comes Along" (Instrumental)
- "I'm Going to Go Back There Someday" - Gonzo
- "America" - Fozzie
- "Animal...Come Back Animal"
- "Finale: The Magic Store" - Company
Awards and nominations
- Gold Record (Soundtrack)
- Platinum Record (Soundtrack)
- Grammy Award - Best Children's Album (Soundtrack)
- Golden Globe Award - Best Song ("Rainbow Connection")
- Academy Award Nomination - Best Song ("Rainbow Connection")
- Academy Award Nomination - Best Original Score (Soundtrack)